Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Neighbour Discovery for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Mike Shaver <shaver@ingenia.com>
9 */
10
11/*
12 * Changes:
13 *
14 * Alexey I. Froloff : RFC6106 (DNSSL) support
15 * Pierre Ynard : export userland ND options
16 * through netlink (RDNSS support)
17 * Lars Fenneberg : fixed MTU setting on receipt
18 * of an RA.
19 * Janos Farkas : kmalloc failure checks
20 * Alexey Kuznetsov : state machine reworked
21 * and moved to net/core.
22 * Pekka Savola : RFC2461 validation
23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
24 */
25
26#define pr_fmt(fmt) "ICMPv6: " fmt
27
28#include <linux/module.h>
29#include <linux/errno.h>
30#include <linux/types.h>
31#include <linux/socket.h>
32#include <linux/sockios.h>
33#include <linux/sched.h>
34#include <linux/net.h>
35#include <linux/in6.h>
36#include <linux/route.h>
37#include <linux/init.h>
38#include <linux/rcupdate.h>
39#include <linux/slab.h>
40#ifdef CONFIG_SYSCTL
41#include <linux/sysctl.h>
42#endif
43
44#include <linux/if_addr.h>
45#include <linux/if_ether.h>
46#include <linux/if_arp.h>
47#include <linux/ipv6.h>
48#include <linux/icmpv6.h>
49#include <linux/jhash.h>
50
51#include <net/sock.h>
52#include <net/snmp.h>
53
54#include <net/ipv6.h>
55#include <net/protocol.h>
56#include <net/ndisc.h>
57#include <net/ip6_route.h>
58#include <net/addrconf.h>
59#include <net/icmp.h>
60
61#include <net/netlink.h>
62#include <linux/rtnetlink.h>
63
64#include <net/flow.h>
65#include <net/ip6_checksum.h>
66#include <net/inet_common.h>
67#include <linux/proc_fs.h>
68
69#include <linux/netfilter.h>
70#include <linux/netfilter_ipv6.h>
71
72static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
74 __u32 *hash_rnd);
75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78static int ndisc_constructor(struct neighbour *neigh);
79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81static int pndisc_constructor(struct pneigh_entry *n);
82static void pndisc_destructor(struct pneigh_entry *n);
83static void pndisc_redo(struct sk_buff *skb);
84static int ndisc_is_multicast(const void *pkey);
85
86static const struct neigh_ops ndisc_generic_ops = {
87 .family = AF_INET6,
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
92};
93
94static const struct neigh_ops ndisc_hh_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
100};
101
102
103static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107};
108
109struct neigh_table nd_tbl = {
110 .family = AF_INET6,
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
113 .hash = ndisc_hash,
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .is_multicast = ndisc_is_multicast,
120 .allow_add = ndisc_allow_add,
121 .id = "ndisc_cache",
122 .parms = {
123 .tbl = &nd_tbl,
124 .reachable_time = ND_REACHABLE_TIME,
125 .data = {
126 [NEIGH_VAR_MCAST_PROBES] = 3,
127 [NEIGH_VAR_UCAST_PROBES] = 3,
128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131 [NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ,
132 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
133 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
134 [NEIGH_VAR_PROXY_QLEN] = 64,
135 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
136 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
137 },
138 },
139 .gc_interval = 30 * HZ,
140 .gc_thresh1 = 128,
141 .gc_thresh2 = 512,
142 .gc_thresh3 = 1024,
143};
144EXPORT_SYMBOL_GPL(nd_tbl);
145
146void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data,
147 int data_len, int pad)
148{
149 int space = __ndisc_opt_addr_space(data_len, pad);
150 u8 *opt = skb_put(skb, space);
151
152 opt[0] = type;
153 opt[1] = space>>3;
154
155 memset(opt + 2, 0, pad);
156 opt += pad;
157 space -= pad;
158
159 memcpy(opt+2, data, data_len);
160 data_len += 2;
161 opt += data_len;
162 space -= data_len;
163 if (space > 0)
164 memset(opt, 0, space);
165}
166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
167
168static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
169 const void *data, u8 icmp6_type)
170{
171 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
172 ndisc_addr_option_pad(skb->dev->type));
173 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
174}
175
176static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
177 void *ha,
178 const u8 *ops_data)
179{
180 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
181 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
182}
183
184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
185 struct nd_opt_hdr *end)
186{
187 int type;
188 if (!cur || !end || cur >= end)
189 return NULL;
190 type = cur->nd_opt_type;
191 do {
192 cur = ((void *)cur) + (cur->nd_opt_len << 3);
193 } while (cur < end && cur->nd_opt_type != type);
194 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
195}
196
197static inline int ndisc_is_useropt(const struct net_device *dev,
198 struct nd_opt_hdr *opt)
199{
200 return opt->nd_opt_type == ND_OPT_PREFIX_INFO ||
201 opt->nd_opt_type == ND_OPT_RDNSS ||
202 opt->nd_opt_type == ND_OPT_DNSSL ||
203 opt->nd_opt_type == ND_OPT_6CO ||
204 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
205 opt->nd_opt_type == ND_OPT_PREF64;
206}
207
208static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
209 struct nd_opt_hdr *cur,
210 struct nd_opt_hdr *end)
211{
212 if (!cur || !end || cur >= end)
213 return NULL;
214 do {
215 cur = ((void *)cur) + (cur->nd_opt_len << 3);
216 } while (cur < end && !ndisc_is_useropt(dev, cur));
217 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
218}
219
220struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
221 u8 *opt, int opt_len,
222 struct ndisc_options *ndopts)
223{
224 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
225
226 if (!nd_opt || opt_len < 0 || !ndopts)
227 return NULL;
228 memset(ndopts, 0, sizeof(*ndopts));
229 while (opt_len) {
230 bool unknown = false;
231 int l;
232 if (opt_len < sizeof(struct nd_opt_hdr))
233 return NULL;
234 l = nd_opt->nd_opt_len << 3;
235 if (opt_len < l || l == 0)
236 return NULL;
237 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
238 goto next_opt;
239 switch (nd_opt->nd_opt_type) {
240 case ND_OPT_SOURCE_LL_ADDR:
241 case ND_OPT_TARGET_LL_ADDR:
242 case ND_OPT_MTU:
243 case ND_OPT_NONCE:
244 case ND_OPT_REDIRECT_HDR:
245 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
246 ND_PRINTK(2, warn,
247 "%s: duplicated ND6 option found: type=%d\n",
248 __func__, nd_opt->nd_opt_type);
249 } else {
250 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
251 }
252 break;
253 case ND_OPT_PREFIX_INFO:
254 ndopts->nd_opts_pi_end = nd_opt;
255 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
256 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
257 break;
258#ifdef CONFIG_IPV6_ROUTE_INFO
259 case ND_OPT_ROUTE_INFO:
260 ndopts->nd_opts_ri_end = nd_opt;
261 if (!ndopts->nd_opts_ri)
262 ndopts->nd_opts_ri = nd_opt;
263 break;
264#endif
265 default:
266 unknown = true;
267 }
268 if (ndisc_is_useropt(dev, nd_opt)) {
269 ndopts->nd_useropts_end = nd_opt;
270 if (!ndopts->nd_useropts)
271 ndopts->nd_useropts = nd_opt;
272 } else if (unknown) {
273 /*
274 * Unknown options must be silently ignored,
275 * to accommodate future extension to the
276 * protocol.
277 */
278 ND_PRINTK(2, notice,
279 "%s: ignored unsupported option; type=%d, len=%d\n",
280 __func__,
281 nd_opt->nd_opt_type,
282 nd_opt->nd_opt_len);
283 }
284next_opt:
285 opt_len -= l;
286 nd_opt = ((void *)nd_opt) + l;
287 }
288 return ndopts;
289}
290
291int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
292{
293 switch (dev->type) {
294 case ARPHRD_ETHER:
295 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
296 case ARPHRD_FDDI:
297 ipv6_eth_mc_map(addr, buf);
298 return 0;
299 case ARPHRD_ARCNET:
300 ipv6_arcnet_mc_map(addr, buf);
301 return 0;
302 case ARPHRD_INFINIBAND:
303 ipv6_ib_mc_map(addr, dev->broadcast, buf);
304 return 0;
305 case ARPHRD_IPGRE:
306 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
307 default:
308 if (dir) {
309 memcpy(buf, dev->broadcast, dev->addr_len);
310 return 0;
311 }
312 }
313 return -EINVAL;
314}
315EXPORT_SYMBOL(ndisc_mc_map);
316
317static u32 ndisc_hash(const void *pkey,
318 const struct net_device *dev,
319 __u32 *hash_rnd)
320{
321 return ndisc_hashfn(pkey, dev, hash_rnd);
322}
323
324static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
325{
326 return neigh_key_eq128(n, pkey);
327}
328
329static int ndisc_constructor(struct neighbour *neigh)
330{
331 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
332 struct net_device *dev = neigh->dev;
333 struct inet6_dev *in6_dev;
334 struct neigh_parms *parms;
335 bool is_multicast = ipv6_addr_is_multicast(addr);
336
337 in6_dev = in6_dev_get(dev);
338 if (!in6_dev) {
339 return -EINVAL;
340 }
341
342 parms = in6_dev->nd_parms;
343 __neigh_parms_put(neigh->parms);
344 neigh->parms = neigh_parms_clone(parms);
345
346 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
347 if (!dev->header_ops) {
348 neigh->nud_state = NUD_NOARP;
349 neigh->ops = &ndisc_direct_ops;
350 neigh->output = neigh_direct_output;
351 } else {
352 if (is_multicast) {
353 neigh->nud_state = NUD_NOARP;
354 ndisc_mc_map(addr, neigh->ha, dev, 1);
355 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
356 neigh->nud_state = NUD_NOARP;
357 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
358 if (dev->flags&IFF_LOOPBACK)
359 neigh->type = RTN_LOCAL;
360 } else if (dev->flags&IFF_POINTOPOINT) {
361 neigh->nud_state = NUD_NOARP;
362 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
363 }
364 if (dev->header_ops->cache)
365 neigh->ops = &ndisc_hh_ops;
366 else
367 neigh->ops = &ndisc_generic_ops;
368 if (neigh->nud_state&NUD_VALID)
369 neigh->output = neigh->ops->connected_output;
370 else
371 neigh->output = neigh->ops->output;
372 }
373 in6_dev_put(in6_dev);
374 return 0;
375}
376
377static int pndisc_constructor(struct pneigh_entry *n)
378{
379 struct in6_addr *addr = (struct in6_addr *)&n->key;
380 struct in6_addr maddr;
381 struct net_device *dev = n->dev;
382
383 if (!dev || !__in6_dev_get(dev))
384 return -EINVAL;
385 addrconf_addr_solict_mult(addr, &maddr);
386 ipv6_dev_mc_inc(dev, &maddr);
387 return 0;
388}
389
390static void pndisc_destructor(struct pneigh_entry *n)
391{
392 struct in6_addr *addr = (struct in6_addr *)&n->key;
393 struct in6_addr maddr;
394 struct net_device *dev = n->dev;
395
396 if (!dev || !__in6_dev_get(dev))
397 return;
398 addrconf_addr_solict_mult(addr, &maddr);
399 ipv6_dev_mc_dec(dev, &maddr);
400}
401
402/* called with rtnl held */
403static bool ndisc_allow_add(const struct net_device *dev,
404 struct netlink_ext_ack *extack)
405{
406 struct inet6_dev *idev = __in6_dev_get(dev);
407
408 if (!idev || idev->cnf.disable_ipv6) {
409 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
410 return false;
411 }
412
413 return true;
414}
415
416static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
417 int len)
418{
419 int hlen = LL_RESERVED_SPACE(dev);
420 int tlen = dev->needed_tailroom;
421 struct sk_buff *skb;
422
423 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
424 if (!skb)
425 return NULL;
426
427 skb->protocol = htons(ETH_P_IPV6);
428 skb->dev = dev;
429
430 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
431 skb_reset_transport_header(skb);
432
433 /* Manually assign socket ownership as we avoid calling
434 * sock_alloc_send_pskb() to bypass wmem buffer limits
435 */
436 rcu_read_lock();
437 skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk);
438 rcu_read_unlock();
439
440 return skb;
441}
442
443static void ip6_nd_hdr(struct sk_buff *skb,
444 const struct in6_addr *saddr,
445 const struct in6_addr *daddr,
446 int hop_limit, int len)
447{
448 struct ipv6hdr *hdr;
449 struct inet6_dev *idev;
450 unsigned tclass;
451
452 rcu_read_lock();
453 idev = __in6_dev_get(skb->dev);
454 tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0;
455 rcu_read_unlock();
456
457 skb_push(skb, sizeof(*hdr));
458 skb_reset_network_header(skb);
459 hdr = ipv6_hdr(skb);
460
461 ip6_flow_hdr(hdr, tclass, 0);
462
463 hdr->payload_len = htons(len);
464 hdr->nexthdr = IPPROTO_ICMPV6;
465 hdr->hop_limit = hop_limit;
466
467 hdr->saddr = *saddr;
468 hdr->daddr = *daddr;
469}
470
471void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr,
472 const struct in6_addr *saddr)
473{
474 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
475 struct dst_entry *dst = skb_dst(skb);
476 struct inet6_dev *idev;
477 struct net *net;
478 struct sock *sk;
479 int err;
480 u8 type;
481
482 type = icmp6h->icmp6_type;
483
484 rcu_read_lock();
485
486 net = dev_net_rcu(skb->dev);
487 sk = net->ipv6.ndisc_sk;
488 if (!dst) {
489 struct flowi6 fl6;
490 int oif = skb->dev->ifindex;
491
492 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
493 dst = icmp6_dst_alloc(skb->dev, &fl6);
494 if (IS_ERR(dst)) {
495 rcu_read_unlock();
496 kfree_skb(skb);
497 return;
498 }
499
500 skb_dst_set(skb, dst);
501 }
502
503 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
504 IPPROTO_ICMPV6,
505 csum_partial(icmp6h,
506 skb->len, 0));
507
508 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
509
510 idev = __in6_dev_get(dst->dev);
511 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
512
513 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
514 net, sk, skb, NULL, dst->dev,
515 dst_output);
516 if (!err) {
517 ICMP6MSGOUT_INC_STATS(net, idev, type);
518 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
519 }
520
521 rcu_read_unlock();
522}
523EXPORT_SYMBOL(ndisc_send_skb);
524
525void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
526 const struct in6_addr *solicited_addr,
527 bool router, bool solicited, bool override, bool inc_opt)
528{
529 struct sk_buff *skb;
530 struct in6_addr tmpaddr;
531 struct inet6_ifaddr *ifp;
532 const struct in6_addr *src_addr;
533 struct nd_msg *msg;
534 int optlen = 0;
535
536 /* for anycast or proxy, solicited_addr != src_addr */
537 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
538 if (ifp) {
539 src_addr = solicited_addr;
540 if (ifp->flags & IFA_F_OPTIMISTIC)
541 override = false;
542 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao);
543 in6_ifa_put(ifp);
544 } else {
545 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
546 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
547 &tmpaddr))
548 return;
549 src_addr = &tmpaddr;
550 }
551
552 if (!dev->addr_len)
553 inc_opt = false;
554 if (inc_opt)
555 optlen += ndisc_opt_addr_space(dev,
556 NDISC_NEIGHBOUR_ADVERTISEMENT);
557
558 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
559 if (!skb)
560 return;
561
562 msg = skb_put(skb, sizeof(*msg));
563 *msg = (struct nd_msg) {
564 .icmph = {
565 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
566 .icmp6_router = router,
567 .icmp6_solicited = solicited,
568 .icmp6_override = override,
569 },
570 .target = *solicited_addr,
571 };
572
573 if (inc_opt)
574 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
575 dev->dev_addr,
576 NDISC_NEIGHBOUR_ADVERTISEMENT);
577
578 ndisc_send_skb(skb, daddr, src_addr);
579}
580
581static void ndisc_send_unsol_na(struct net_device *dev)
582{
583 struct inet6_dev *idev;
584 struct inet6_ifaddr *ifa;
585
586 idev = in6_dev_get(dev);
587 if (!idev)
588 return;
589
590 read_lock_bh(&idev->lock);
591 list_for_each_entry(ifa, &idev->addr_list, if_list) {
592 /* skip tentative addresses until dad completes */
593 if (ifa->flags & IFA_F_TENTATIVE &&
594 !(ifa->flags & IFA_F_OPTIMISTIC))
595 continue;
596
597 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
598 /*router=*/ !!idev->cnf.forwarding,
599 /*solicited=*/ false, /*override=*/ true,
600 /*inc_opt=*/ true);
601 }
602 read_unlock_bh(&idev->lock);
603
604 in6_dev_put(idev);
605}
606
607struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit,
608 const struct in6_addr *saddr, u64 nonce)
609{
610 int inc_opt = dev->addr_len;
611 struct sk_buff *skb;
612 struct nd_msg *msg;
613 int optlen = 0;
614
615 if (!saddr)
616 return NULL;
617
618 if (ipv6_addr_any(saddr))
619 inc_opt = false;
620 if (inc_opt)
621 optlen += ndisc_opt_addr_space(dev,
622 NDISC_NEIGHBOUR_SOLICITATION);
623 if (nonce != 0)
624 optlen += 8;
625
626 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
627 if (!skb)
628 return NULL;
629
630 msg = skb_put(skb, sizeof(*msg));
631 *msg = (struct nd_msg) {
632 .icmph = {
633 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
634 },
635 .target = *solicit,
636 };
637
638 if (inc_opt)
639 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
640 dev->dev_addr,
641 NDISC_NEIGHBOUR_SOLICITATION);
642 if (nonce != 0) {
643 u8 *opt = skb_put(skb, 8);
644
645 opt[0] = ND_OPT_NONCE;
646 opt[1] = 8 >> 3;
647 memcpy(opt + 2, &nonce, 6);
648 }
649
650 return skb;
651}
652EXPORT_SYMBOL(ndisc_ns_create);
653
654void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
655 const struct in6_addr *daddr, const struct in6_addr *saddr,
656 u64 nonce)
657{
658 struct in6_addr addr_buf;
659 struct sk_buff *skb;
660
661 if (!saddr) {
662 if (ipv6_get_lladdr(dev, &addr_buf,
663 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC)))
664 return;
665 saddr = &addr_buf;
666 }
667
668 skb = ndisc_ns_create(dev, solicit, saddr, nonce);
669
670 if (skb)
671 ndisc_send_skb(skb, daddr, saddr);
672}
673
674void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
675 const struct in6_addr *daddr)
676{
677 struct sk_buff *skb;
678 struct rs_msg *msg;
679 int send_sllao = dev->addr_len;
680 int optlen = 0;
681
682#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
683 /*
684 * According to section 2.2 of RFC 4429, we must not
685 * send router solicitations with a sllao from
686 * optimistic addresses, but we may send the solicitation
687 * if we don't include the sllao. So here we check
688 * if our address is optimistic, and if so, we
689 * suppress the inclusion of the sllao.
690 */
691 if (send_sllao) {
692 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
693 dev, 1);
694 if (ifp) {
695 if (ifp->flags & IFA_F_OPTIMISTIC) {
696 send_sllao = 0;
697 }
698 in6_ifa_put(ifp);
699 } else {
700 send_sllao = 0;
701 }
702 }
703#endif
704 if (send_sllao)
705 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
706
707 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
708 if (!skb)
709 return;
710
711 msg = skb_put(skb, sizeof(*msg));
712 *msg = (struct rs_msg) {
713 .icmph = {
714 .icmp6_type = NDISC_ROUTER_SOLICITATION,
715 },
716 };
717
718 if (send_sllao)
719 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
720 dev->dev_addr,
721 NDISC_ROUTER_SOLICITATION);
722
723 ndisc_send_skb(skb, daddr, saddr);
724}
725
726
727static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
728{
729 /*
730 * "The sender MUST return an ICMP
731 * destination unreachable"
732 */
733 dst_link_failure(skb);
734 kfree_skb(skb);
735}
736
737/* Called with locked neigh: either read or both */
738
739static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
740{
741 struct in6_addr *saddr = NULL;
742 struct in6_addr mcaddr;
743 struct net_device *dev = neigh->dev;
744 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
745 int probes = atomic_read(&neigh->probes);
746
747 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
748 dev, false, 1,
749 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
750 saddr = &ipv6_hdr(skb)->saddr;
751 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
752 if (probes < 0) {
753 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) {
754 ND_PRINTK(1, dbg,
755 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
756 __func__, target);
757 }
758 ndisc_send_ns(dev, target, target, saddr, 0);
759 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
760 neigh_app_ns(neigh);
761 } else {
762 addrconf_addr_solict_mult(target, &mcaddr);
763 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
764 }
765}
766
767static int pndisc_is_router(const void *pkey,
768 struct net_device *dev)
769{
770 struct pneigh_entry *n;
771 int ret = -1;
772
773 read_lock_bh(&nd_tbl.lock);
774 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
775 if (n)
776 ret = !!(n->flags & NTF_ROUTER);
777 read_unlock_bh(&nd_tbl.lock);
778
779 return ret;
780}
781
782void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
783 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
784 struct ndisc_options *ndopts)
785{
786 neigh_update(neigh, lladdr, new, flags, 0);
787 /* report ndisc ops about neighbour update */
788 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
789}
790
791static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
792{
793 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
794 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
795 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
796 u8 *lladdr = NULL;
797 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
798 offsetof(struct nd_msg, opt));
799 struct ndisc_options ndopts;
800 struct net_device *dev = skb->dev;
801 struct inet6_ifaddr *ifp;
802 struct inet6_dev *idev = NULL;
803 struct neighbour *neigh;
804 int dad = ipv6_addr_any(saddr);
805 int is_router = -1;
806 SKB_DR(reason);
807 u64 nonce = 0;
808 bool inc;
809
810 if (skb->len < sizeof(struct nd_msg))
811 return SKB_DROP_REASON_PKT_TOO_SMALL;
812
813 if (ipv6_addr_is_multicast(&msg->target)) {
814 ND_PRINTK(2, warn, "NS: multicast target address\n");
815 return reason;
816 }
817
818 /*
819 * RFC2461 7.1.1:
820 * DAD has to be destined for solicited node multicast address.
821 */
822 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
823 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
824 return reason;
825 }
826
827 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
828 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
829
830 if (ndopts.nd_opts_src_lladdr) {
831 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
832 if (!lladdr) {
833 ND_PRINTK(2, warn,
834 "NS: invalid link-layer address length\n");
835 return reason;
836 }
837
838 /* RFC2461 7.1.1:
839 * If the IP source address is the unspecified address,
840 * there MUST NOT be source link-layer address option
841 * in the message.
842 */
843 if (dad) {
844 ND_PRINTK(2, warn,
845 "NS: bad DAD packet (link-layer address option)\n");
846 return reason;
847 }
848 }
849 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
850 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
851
852 inc = ipv6_addr_is_multicast(daddr);
853
854 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
855 if (ifp) {
856have_ifp:
857 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
858 if (dad) {
859 if (nonce != 0 && ifp->dad_nonce == nonce) {
860 u8 *np = (u8 *)&nonce;
861 /* Matching nonce if looped back */
862 ND_PRINTK(2, notice,
863 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
864 ifp->idev->dev->name,
865 &ifp->addr, np);
866 goto out;
867 }
868 /*
869 * We are colliding with another node
870 * who is doing DAD
871 * so fail our DAD process
872 */
873 addrconf_dad_failure(skb, ifp);
874 return reason;
875 } else {
876 /*
877 * This is not a dad solicitation.
878 * If we are an optimistic node,
879 * we should respond.
880 * Otherwise, we should ignore it.
881 */
882 if (!(ifp->flags & IFA_F_OPTIMISTIC))
883 goto out;
884 }
885 }
886
887 idev = ifp->idev;
888 } else {
889 struct net *net = dev_net(dev);
890
891 /* perhaps an address on the master device */
892 if (netif_is_l3_slave(dev)) {
893 struct net_device *mdev;
894
895 mdev = netdev_master_upper_dev_get_rcu(dev);
896 if (mdev) {
897 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
898 if (ifp)
899 goto have_ifp;
900 }
901 }
902
903 idev = in6_dev_get(dev);
904 if (!idev) {
905 /* XXX: count this drop? */
906 return reason;
907 }
908
909 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
910 (READ_ONCE(idev->cnf.forwarding) &&
911 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
912 READ_ONCE(idev->cnf.proxy_ndp)) &&
913 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
914 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
915 skb->pkt_type != PACKET_HOST &&
916 inc &&
917 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
918 /*
919 * for anycast or proxy,
920 * sender should delay its response
921 * by a random time between 0 and
922 * MAX_ANYCAST_DELAY_TIME seconds.
923 * (RFC2461) -- yoshfuji
924 */
925 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
926 if (n)
927 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
928 goto out;
929 }
930 } else {
931 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST);
932 goto out;
933 }
934 }
935
936 if (is_router < 0)
937 is_router = READ_ONCE(idev->cnf.forwarding);
938
939 if (dad) {
940 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
941 !!is_router, false, (ifp != NULL), true);
942 goto out;
943 }
944
945 if (inc)
946 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
947 else
948 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
949
950 /*
951 * update / create cache entry
952 * for the source address
953 */
954 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
955 !inc || lladdr || !dev->addr_len);
956 if (neigh)
957 ndisc_update(dev, neigh, lladdr, NUD_STALE,
958 NEIGH_UPDATE_F_WEAK_OVERRIDE|
959 NEIGH_UPDATE_F_OVERRIDE,
960 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
961 if (neigh || !dev->header_ops) {
962 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
963 true, (ifp != NULL && inc), inc);
964 if (neigh)
965 neigh_release(neigh);
966 reason = SKB_CONSUMED;
967 }
968
969out:
970 if (ifp)
971 in6_ifa_put(ifp);
972 else
973 in6_dev_put(idev);
974 return reason;
975}
976
977static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
978{
979 struct inet6_dev *idev = __in6_dev_get(dev);
980
981 switch (READ_ONCE(idev->cnf.accept_untracked_na)) {
982 case 0: /* Don't accept untracked na (absent in neighbor cache) */
983 return 0;
984 case 1: /* Create new entries from na if currently untracked */
985 return 1;
986 case 2: /* Create new entries from untracked na only if saddr is in the
987 * same subnet as an address configured on the interface that
988 * received the na
989 */
990 return !!ipv6_chk_prefix(saddr, dev);
991 default:
992 return 0;
993 }
994}
995
996static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
997{
998 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
999 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1000 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
1001 u8 *lladdr = NULL;
1002 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1003 offsetof(struct nd_msg, opt));
1004 struct ndisc_options ndopts;
1005 struct net_device *dev = skb->dev;
1006 struct inet6_dev *idev = __in6_dev_get(dev);
1007 struct inet6_ifaddr *ifp;
1008 struct neighbour *neigh;
1009 SKB_DR(reason);
1010 u8 new_state;
1011
1012 if (skb->len < sizeof(struct nd_msg))
1013 return SKB_DROP_REASON_PKT_TOO_SMALL;
1014
1015 if (ipv6_addr_is_multicast(&msg->target)) {
1016 ND_PRINTK(2, warn, "NA: target address is multicast\n");
1017 return reason;
1018 }
1019
1020 if (ipv6_addr_is_multicast(daddr) &&
1021 msg->icmph.icmp6_solicited) {
1022 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
1023 return reason;
1024 }
1025
1026 /* For some 802.11 wireless deployments (and possibly other networks),
1027 * there will be a NA proxy and unsolicitd packets are attacks
1028 * and thus should not be accepted.
1029 * drop_unsolicited_na takes precedence over accept_untracked_na
1030 */
1031 if (!msg->icmph.icmp6_solicited && idev &&
1032 READ_ONCE(idev->cnf.drop_unsolicited_na))
1033 return reason;
1034
1035 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
1036 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1037
1038 if (ndopts.nd_opts_tgt_lladdr) {
1039 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
1040 if (!lladdr) {
1041 ND_PRINTK(2, warn,
1042 "NA: invalid link-layer address length\n");
1043 return reason;
1044 }
1045 }
1046 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1047 if (ifp) {
1048 if (skb->pkt_type != PACKET_LOOPBACK
1049 && (ifp->flags & IFA_F_TENTATIVE)) {
1050 addrconf_dad_failure(skb, ifp);
1051 return reason;
1052 }
1053 /* What should we make now? The advertisement
1054 is invalid, but ndisc specs say nothing
1055 about it. It could be misconfiguration, or
1056 an smart proxy agent tries to help us :-)
1057
1058 We should not print the error if NA has been
1059 received from loopback - it is just our own
1060 unsolicited advertisement.
1061 */
1062 if (skb->pkt_type != PACKET_LOOPBACK)
1063 ND_PRINTK(1, warn,
1064 "NA: %pM advertised our address %pI6c on %s!\n",
1065 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1066 in6_ifa_put(ifp);
1067 return reason;
1068 }
1069
1070 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1071
1072 /* RFC 9131 updates original Neighbour Discovery RFC 4861.
1073 * NAs with Target LL Address option without a corresponding
1074 * entry in the neighbour cache can now create a STALE neighbour
1075 * cache entry on routers.
1076 *
1077 * entry accept fwding solicited behaviour
1078 * ------- ------ ------ --------- ----------------------
1079 * present X X 0 Set state to STALE
1080 * present X X 1 Set state to REACHABLE
1081 * absent 0 X X Do nothing
1082 * absent 1 0 X Do nothing
1083 * absent 1 1 X Add a new STALE entry
1084 *
1085 * Note that we don't do a (daddr == all-routers-mcast) check.
1086 */
1087 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE;
1088 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) {
1089 if (accept_untracked_na(dev, saddr)) {
1090 neigh = neigh_create(&nd_tbl, &msg->target, dev);
1091 new_state = NUD_STALE;
1092 }
1093 }
1094
1095 if (neigh && !IS_ERR(neigh)) {
1096 u8 old_flags = neigh->flags;
1097 struct net *net = dev_net(dev);
1098
1099 if (READ_ONCE(neigh->nud_state) & NUD_FAILED)
1100 goto out;
1101
1102 /*
1103 * Don't update the neighbor cache entry on a proxy NA from
1104 * ourselves because either the proxied node is off link or it
1105 * has already sent a NA to us.
1106 */
1107 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1108 READ_ONCE(net->ipv6.devconf_all->forwarding) &&
1109 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
1110 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1111 /* XXX: idev->cnf.proxy_ndp */
1112 goto out;
1113 }
1114
1115 ndisc_update(dev, neigh, lladdr,
1116 new_state,
1117 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1118 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1119 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1120 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1121 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1122
1123 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1124 /*
1125 * Change: router to host
1126 */
1127 rt6_clean_tohost(dev_net(dev), saddr);
1128 }
1129 reason = SKB_CONSUMED;
1130out:
1131 neigh_release(neigh);
1132 }
1133 return reason;
1134}
1135
1136static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
1137{
1138 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1139 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1140 struct neighbour *neigh;
1141 struct inet6_dev *idev;
1142 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1143 struct ndisc_options ndopts;
1144 u8 *lladdr = NULL;
1145 SKB_DR(reason);
1146
1147 if (skb->len < sizeof(*rs_msg))
1148 return SKB_DROP_REASON_PKT_TOO_SMALL;
1149
1150 idev = __in6_dev_get(skb->dev);
1151 if (!idev) {
1152 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1153 return reason;
1154 }
1155
1156 /* Don't accept RS if we're not in router mode */
1157 if (!READ_ONCE(idev->cnf.forwarding))
1158 goto out;
1159
1160 /*
1161 * Don't update NCE if src = ::;
1162 * this implies that the source node has no ip address assigned yet.
1163 */
1164 if (ipv6_addr_any(saddr))
1165 goto out;
1166
1167 /* Parse ND options */
1168 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
1169 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1170
1171 if (ndopts.nd_opts_src_lladdr) {
1172 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1173 skb->dev);
1174 if (!lladdr)
1175 goto out;
1176 }
1177
1178 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1179 if (neigh) {
1180 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1181 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1182 NEIGH_UPDATE_F_OVERRIDE|
1183 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1184 NDISC_ROUTER_SOLICITATION, &ndopts);
1185 neigh_release(neigh);
1186 reason = SKB_CONSUMED;
1187 }
1188out:
1189 return reason;
1190}
1191
1192static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1193{
1194 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1195 struct sk_buff *skb;
1196 struct nlmsghdr *nlh;
1197 struct nduseroptmsg *ndmsg;
1198 struct net *net = dev_net(ra->dev);
1199 int err;
1200 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1201 + (opt->nd_opt_len << 3));
1202 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1203
1204 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1205 if (!skb) {
1206 err = -ENOBUFS;
1207 goto errout;
1208 }
1209
1210 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1211 if (!nlh) {
1212 goto nla_put_failure;
1213 }
1214
1215 ndmsg = nlmsg_data(nlh);
1216 ndmsg->nduseropt_family = AF_INET6;
1217 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1218 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1219 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1220 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1221
1222 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1223
1224 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1225 goto nla_put_failure;
1226 nlmsg_end(skb, nlh);
1227
1228 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1229 return;
1230
1231nla_put_failure:
1232 nlmsg_free(skb);
1233 err = -EMSGSIZE;
1234errout:
1235 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1236}
1237
1238static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
1239{
1240 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1241 bool send_ifinfo_notify = false;
1242 struct neighbour *neigh = NULL;
1243 struct ndisc_options ndopts;
1244 struct fib6_info *rt = NULL;
1245 struct inet6_dev *in6_dev;
1246 struct fib6_table *table;
1247 u32 defrtr_usr_metric;
1248 unsigned int pref = 0;
1249 __u32 old_if_flags;
1250 struct net *net;
1251 SKB_DR(reason);
1252 int lifetime;
1253 int optlen;
1254
1255 __u8 *opt = (__u8 *)(ra_msg + 1);
1256
1257 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1258 sizeof(struct ra_msg);
1259
1260 ND_PRINTK(2, info,
1261 "RA: %s, dev: %s\n",
1262 __func__, skb->dev->name);
1263 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1264 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1265 return reason;
1266 }
1267 if (optlen < 0)
1268 return SKB_DROP_REASON_PKT_TOO_SMALL;
1269
1270#ifdef CONFIG_IPV6_NDISC_NODETYPE
1271 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1272 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1273 return reason;
1274 }
1275#endif
1276
1277 in6_dev = __in6_dev_get(skb->dev);
1278 if (!in6_dev) {
1279 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1280 skb->dev->name);
1281 return reason;
1282 }
1283
1284 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
1285 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1286
1287 if (!ipv6_accept_ra(in6_dev)) {
1288 ND_PRINTK(2, info,
1289 "RA: %s, did not accept ra for dev: %s\n",
1290 __func__, skb->dev->name);
1291 goto skip_linkparms;
1292 }
1293
1294#ifdef CONFIG_IPV6_NDISC_NODETYPE
1295 /* skip link-specific parameters from interior routers */
1296 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1297 ND_PRINTK(2, info,
1298 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1299 __func__, skb->dev->name);
1300 goto skip_linkparms;
1301 }
1302#endif
1303
1304 if (in6_dev->if_flags & IF_RS_SENT) {
1305 /*
1306 * flag that an RA was received after an RS was sent
1307 * out on this interface.
1308 */
1309 in6_dev->if_flags |= IF_RA_RCVD;
1310 }
1311
1312 /*
1313 * Remember the managed/otherconf flags from most recently
1314 * received RA message (RFC 2462) -- yoshfuji
1315 */
1316 old_if_flags = in6_dev->if_flags;
1317 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1318 IF_RA_OTHERCONF)) |
1319 (ra_msg->icmph.icmp6_addrconf_managed ?
1320 IF_RA_MANAGED : 0) |
1321 (ra_msg->icmph.icmp6_addrconf_other ?
1322 IF_RA_OTHERCONF : 0);
1323
1324 if (old_if_flags != in6_dev->if_flags)
1325 send_ifinfo_notify = true;
1326
1327 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) {
1328 ND_PRINTK(2, info,
1329 "RA: %s, defrtr is false for dev: %s\n",
1330 __func__, skb->dev->name);
1331 goto skip_defrtr;
1332 }
1333
1334 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1335 if (lifetime != 0 &&
1336 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) {
1337 ND_PRINTK(2, info,
1338 "RA: router lifetime (%ds) is too short: %s\n",
1339 lifetime, skb->dev->name);
1340 goto skip_defrtr;
1341 }
1342
1343 /* Do not accept RA with source-addr found on local machine unless
1344 * accept_ra_from_local is set to true.
1345 */
1346 net = dev_net(in6_dev->dev);
1347 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1348 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1349 ND_PRINTK(2, info,
1350 "RA from local address detected on dev: %s: default router ignored\n",
1351 skb->dev->name);
1352 goto skip_defrtr;
1353 }
1354
1355#ifdef CONFIG_IPV6_ROUTER_PREF
1356 pref = ra_msg->icmph.icmp6_router_pref;
1357 /* 10b is handled as if it were 00b (medium) */
1358 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1359 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref))
1360 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1361#endif
1362 /* routes added from RAs do not use nexthop objects */
1363 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1364 if (rt) {
1365 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1366 rt->fib6_nh->fib_nh_dev, NULL,
1367 &ipv6_hdr(skb)->saddr);
1368 if (!neigh) {
1369 ND_PRINTK(0, err,
1370 "RA: %s got default router without neighbour\n",
1371 __func__);
1372 fib6_info_release(rt);
1373 return reason;
1374 }
1375 }
1376 /* Set default route metric as specified by user */
1377 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1378 /* delete the route if lifetime is 0 or if metric needs change */
1379 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1380 ip6_del_rt(net, rt, false);
1381 rt = NULL;
1382 }
1383
1384 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1385 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1386 if (!rt && lifetime) {
1387 ND_PRINTK(3, info, "RA: adding default router\n");
1388
1389 if (neigh)
1390 neigh_release(neigh);
1391
1392 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1393 skb->dev, pref, defrtr_usr_metric,
1394 lifetime);
1395 if (!rt) {
1396 ND_PRINTK(0, err,
1397 "RA: %s failed to add default route\n",
1398 __func__);
1399 return reason;
1400 }
1401
1402 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1403 rt->fib6_nh->fib_nh_dev, NULL,
1404 &ipv6_hdr(skb)->saddr);
1405 if (!neigh) {
1406 ND_PRINTK(0, err,
1407 "RA: %s got default router without neighbour\n",
1408 __func__);
1409 fib6_info_release(rt);
1410 return reason;
1411 }
1412 neigh->flags |= NTF_ROUTER;
1413 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) {
1414 struct nl_info nlinfo = {
1415 .nl_net = net,
1416 };
1417 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1418 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE);
1419 }
1420
1421 if (rt) {
1422 table = rt->fib6_table;
1423 spin_lock_bh(&table->tb6_lock);
1424
1425 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1426 fib6_add_gc_list(rt);
1427
1428 spin_unlock_bh(&table->tb6_lock);
1429 }
1430 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 &&
1431 ra_msg->icmph.icmp6_hop_limit) {
1432 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <=
1433 ra_msg->icmph.icmp6_hop_limit) {
1434 WRITE_ONCE(in6_dev->cnf.hop_limit,
1435 ra_msg->icmph.icmp6_hop_limit);
1436 fib6_metric_set(rt, RTAX_HOPLIMIT,
1437 ra_msg->icmph.icmp6_hop_limit);
1438 } else {
1439 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1440 }
1441 }
1442
1443skip_defrtr:
1444
1445 /*
1446 * Update Reachable Time and Retrans Timer
1447 */
1448
1449 if (in6_dev->nd_parms) {
1450 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1451
1452 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1453 rtime = (rtime*HZ)/1000;
1454 if (rtime < HZ/100)
1455 rtime = HZ/100;
1456 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1457 in6_dev->tstamp = jiffies;
1458 send_ifinfo_notify = true;
1459 }
1460
1461 rtime = ntohl(ra_msg->reachable_time);
1462 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1463 rtime = (rtime*HZ)/1000;
1464
1465 if (rtime < HZ/10)
1466 rtime = HZ/10;
1467
1468 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1469 NEIGH_VAR_SET(in6_dev->nd_parms,
1470 BASE_REACHABLE_TIME, rtime);
1471 NEIGH_VAR_SET(in6_dev->nd_parms,
1472 GC_STALETIME, 3 * rtime);
1473 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1474 in6_dev->tstamp = jiffies;
1475 send_ifinfo_notify = true;
1476 }
1477 }
1478 }
1479
1480skip_linkparms:
1481
1482 /*
1483 * Process options.
1484 */
1485
1486 if (!neigh)
1487 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1488 skb->dev, 1);
1489 if (neigh) {
1490 u8 *lladdr = NULL;
1491 if (ndopts.nd_opts_src_lladdr) {
1492 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1493 skb->dev);
1494 if (!lladdr) {
1495 ND_PRINTK(2, warn,
1496 "RA: invalid link-layer address length\n");
1497 goto out;
1498 }
1499 }
1500 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1501 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1502 NEIGH_UPDATE_F_OVERRIDE|
1503 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1504 NEIGH_UPDATE_F_ISROUTER,
1505 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1506 reason = SKB_CONSUMED;
1507 }
1508
1509 if (!ipv6_accept_ra(in6_dev)) {
1510 ND_PRINTK(2, info,
1511 "RA: %s, accept_ra is false for dev: %s\n",
1512 __func__, skb->dev->name);
1513 goto out;
1514 }
1515
1516#ifdef CONFIG_IPV6_ROUTE_INFO
1517 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) &&
1518 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1519 in6_dev->dev, 0)) {
1520 ND_PRINTK(2, info,
1521 "RA from local address detected on dev: %s: router info ignored.\n",
1522 skb->dev->name);
1523 goto skip_routeinfo;
1524 }
1525
1526 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) {
1527 struct nd_opt_hdr *p;
1528 for (p = ndopts.nd_opts_ri;
1529 p;
1530 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1531 struct route_info *ri = (struct route_info *)p;
1532#ifdef CONFIG_IPV6_NDISC_NODETYPE
1533 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1534 ri->prefix_len == 0)
1535 continue;
1536#endif
1537 if (ri->prefix_len == 0 &&
1538 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr))
1539 continue;
1540 if (ri->lifetime != 0 &&
1541 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft))
1542 continue;
1543 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen))
1544 continue;
1545 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen))
1546 continue;
1547 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1548 &ipv6_hdr(skb)->saddr);
1549 }
1550 }
1551
1552skip_routeinfo:
1553#endif
1554
1555#ifdef CONFIG_IPV6_NDISC_NODETYPE
1556 /* skip link-specific ndopts from interior routers */
1557 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1558 ND_PRINTK(2, info,
1559 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1560 __func__, skb->dev->name);
1561 goto out;
1562 }
1563#endif
1564
1565 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) {
1566 struct nd_opt_hdr *p;
1567 for (p = ndopts.nd_opts_pi;
1568 p;
1569 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1570 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1571 (p->nd_opt_len) << 3,
1572 ndopts.nd_opts_src_lladdr != NULL);
1573 }
1574 }
1575
1576 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) {
1577 __be32 n;
1578 u32 mtu;
1579
1580 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1581 mtu = ntohl(n);
1582
1583 if (in6_dev->ra_mtu != mtu) {
1584 in6_dev->ra_mtu = mtu;
1585 send_ifinfo_notify = true;
1586 }
1587
1588 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1589 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1590 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) {
1591 WRITE_ONCE(in6_dev->cnf.mtu6, mtu);
1592 fib6_metric_set(rt, RTAX_MTU, mtu);
1593 rt6_mtu_change(skb->dev, mtu);
1594 }
1595 }
1596
1597 if (ndopts.nd_useropts) {
1598 struct nd_opt_hdr *p;
1599 for (p = ndopts.nd_useropts;
1600 p;
1601 p = ndisc_next_useropt(skb->dev, p,
1602 ndopts.nd_useropts_end)) {
1603 ndisc_ra_useropt(skb, p);
1604 }
1605 }
1606
1607 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1608 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1609 }
1610out:
1611 /* Send a notify if RA changed managed/otherconf flags or
1612 * timer settings or ra_mtu value
1613 */
1614 if (send_ifinfo_notify)
1615 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1616
1617 fib6_info_release(rt);
1618 if (neigh)
1619 neigh_release(neigh);
1620 return reason;
1621}
1622
1623static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
1624{
1625 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1626 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1627 offsetof(struct rd_msg, opt));
1628 struct ndisc_options ndopts;
1629 SKB_DR(reason);
1630 u8 *hdr;
1631
1632#ifdef CONFIG_IPV6_NDISC_NODETYPE
1633 switch (skb->ndisc_nodetype) {
1634 case NDISC_NODETYPE_HOST:
1635 case NDISC_NODETYPE_NODEFAULT:
1636 ND_PRINTK(2, warn,
1637 "Redirect: from host or unauthorized router\n");
1638 return reason;
1639 }
1640#endif
1641
1642 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1643 ND_PRINTK(2, warn,
1644 "Redirect: source address is not link-local\n");
1645 return reason;
1646 }
1647
1648 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1649 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
1650
1651 if (!ndopts.nd_opts_rh) {
1652 ip6_redirect_no_header(skb, dev_net(skb->dev),
1653 skb->dev->ifindex);
1654 return reason;
1655 }
1656
1657 hdr = (u8 *)ndopts.nd_opts_rh;
1658 hdr += 8;
1659 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1660 return SKB_DROP_REASON_PKT_TOO_SMALL;
1661
1662 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1663}
1664
1665static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1666 struct sk_buff *orig_skb,
1667 int rd_len)
1668{
1669 u8 *opt = skb_put(skb, rd_len);
1670
1671 memset(opt, 0, 8);
1672 *(opt++) = ND_OPT_REDIRECT_HDR;
1673 *(opt++) = (rd_len >> 3);
1674 opt += 6;
1675
1676 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1677 rd_len - 8);
1678}
1679
1680void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1681{
1682 struct net_device *dev = skb->dev;
1683 struct net *net = dev_net(dev);
1684 struct sock *sk = net->ipv6.ndisc_sk;
1685 int optlen = 0;
1686 struct inet_peer *peer;
1687 struct sk_buff *buff;
1688 struct rd_msg *msg;
1689 struct in6_addr saddr_buf;
1690 struct rt6_info *rt;
1691 struct dst_entry *dst;
1692 struct flowi6 fl6;
1693 int rd_len;
1694 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1695 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1696 bool ret;
1697
1698 if (netif_is_l3_master(skb->dev)) {
1699 dev = dev_get_by_index_rcu(dev_net(skb->dev), IPCB(skb)->iif);
1700 if (!dev)
1701 return;
1702 }
1703
1704 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1705 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1706 dev->name);
1707 return;
1708 }
1709
1710 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1711 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1712 ND_PRINTK(2, warn,
1713 "Redirect: target address is not link-local unicast\n");
1714 return;
1715 }
1716
1717 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1718 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1719
1720 dst = ip6_route_output(net, NULL, &fl6);
1721 if (dst->error) {
1722 dst_release(dst);
1723 return;
1724 }
1725 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1726 if (IS_ERR(dst))
1727 return;
1728
1729 rt = dst_rt6_info(dst);
1730
1731 if (rt->rt6i_flags & RTF_GATEWAY) {
1732 ND_PRINTK(2, warn,
1733 "Redirect: destination is not a neighbour\n");
1734 goto release;
1735 }
1736
1737 rcu_read_lock();
1738 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr);
1739 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1740 rcu_read_unlock();
1741
1742 if (!ret)
1743 goto release;
1744
1745 if (dev->addr_len) {
1746 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1747 if (!neigh) {
1748 ND_PRINTK(2, warn,
1749 "Redirect: no neigh for target address\n");
1750 goto release;
1751 }
1752
1753 read_lock_bh(&neigh->lock);
1754 if (neigh->nud_state & NUD_VALID) {
1755 memcpy(ha_buf, neigh->ha, dev->addr_len);
1756 read_unlock_bh(&neigh->lock);
1757 ha = ha_buf;
1758 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1759 ops_data_buf,
1760 &ops_data);
1761 } else
1762 read_unlock_bh(&neigh->lock);
1763
1764 neigh_release(neigh);
1765 }
1766
1767 rd_len = min_t(unsigned int,
1768 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1769 skb->len + 8);
1770 rd_len &= ~0x7;
1771 optlen += rd_len;
1772
1773 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1774 if (!buff)
1775 goto release;
1776
1777 msg = skb_put(buff, sizeof(*msg));
1778 *msg = (struct rd_msg) {
1779 .icmph = {
1780 .icmp6_type = NDISC_REDIRECT,
1781 },
1782 .target = *target,
1783 .dest = ipv6_hdr(skb)->daddr,
1784 };
1785
1786 /*
1787 * include target_address option
1788 */
1789
1790 if (ha)
1791 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1792
1793 /*
1794 * build redirect option and copy skb over to the new packet.
1795 */
1796
1797 if (rd_len)
1798 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1799
1800 skb_dst_set(buff, dst);
1801 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1802 return;
1803
1804release:
1805 dst_release(dst);
1806}
1807
1808static void pndisc_redo(struct sk_buff *skb)
1809{
1810 enum skb_drop_reason reason = ndisc_recv_ns(skb);
1811
1812 kfree_skb_reason(skb, reason);
1813}
1814
1815static int ndisc_is_multicast(const void *pkey)
1816{
1817 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1818}
1819
1820static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1821{
1822 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1823
1824 if (!idev)
1825 return true;
1826 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1827 READ_ONCE(idev->cnf.suppress_frag_ndisc)) {
1828 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1829 return true;
1830 }
1831 return false;
1832}
1833
1834enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
1835{
1836 struct nd_msg *msg;
1837 SKB_DR(reason);
1838
1839 if (ndisc_suppress_frag_ndisc(skb))
1840 return SKB_DROP_REASON_IPV6_NDISC_FRAG;
1841
1842 if (skb_linearize(skb))
1843 return SKB_DROP_REASON_NOMEM;
1844
1845 msg = (struct nd_msg *)skb_transport_header(skb);
1846
1847 __skb_push(skb, skb->data - skb_transport_header(skb));
1848
1849 if (ipv6_hdr(skb)->hop_limit != 255) {
1850 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1851 ipv6_hdr(skb)->hop_limit);
1852 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT;
1853 }
1854
1855 if (msg->icmph.icmp6_code != 0) {
1856 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1857 msg->icmph.icmp6_code);
1858 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE;
1859 }
1860
1861 switch (msg->icmph.icmp6_type) {
1862 case NDISC_NEIGHBOUR_SOLICITATION:
1863 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1864 reason = ndisc_recv_ns(skb);
1865 break;
1866
1867 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1868 reason = ndisc_recv_na(skb);
1869 break;
1870
1871 case NDISC_ROUTER_SOLICITATION:
1872 reason = ndisc_recv_rs(skb);
1873 break;
1874
1875 case NDISC_ROUTER_ADVERTISEMENT:
1876 reason = ndisc_router_discovery(skb);
1877 break;
1878
1879 case NDISC_REDIRECT:
1880 reason = ndisc_redirect_rcv(skb);
1881 break;
1882 }
1883
1884 return reason;
1885}
1886
1887static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1888{
1889 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1890 struct netdev_notifier_change_info *change_info;
1891 struct net *net = dev_net(dev);
1892 struct inet6_dev *idev;
1893 bool evict_nocarrier;
1894
1895 switch (event) {
1896 case NETDEV_CHANGEADDR:
1897 neigh_changeaddr(&nd_tbl, dev);
1898 fib6_run_gc(0, net, false);
1899 fallthrough;
1900 case NETDEV_UP:
1901 idev = in6_dev_get(dev);
1902 if (!idev)
1903 break;
1904 if (READ_ONCE(idev->cnf.ndisc_notify) ||
1905 READ_ONCE(net->ipv6.devconf_all->ndisc_notify))
1906 ndisc_send_unsol_na(dev);
1907 in6_dev_put(idev);
1908 break;
1909 case NETDEV_CHANGE:
1910 idev = in6_dev_get(dev);
1911 if (!idev)
1912 evict_nocarrier = true;
1913 else {
1914 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) &&
1915 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier);
1916 in6_dev_put(idev);
1917 }
1918
1919 change_info = ptr;
1920 if (change_info->flags_changed & IFF_NOARP)
1921 neigh_changeaddr(&nd_tbl, dev);
1922 if (evict_nocarrier && !netif_carrier_ok(dev))
1923 neigh_carrier_down(&nd_tbl, dev);
1924 break;
1925 case NETDEV_DOWN:
1926 neigh_ifdown(&nd_tbl, dev);
1927 fib6_run_gc(0, net, false);
1928 break;
1929 case NETDEV_NOTIFY_PEERS:
1930 ndisc_send_unsol_na(dev);
1931 break;
1932 default:
1933 break;
1934 }
1935
1936 return NOTIFY_DONE;
1937}
1938
1939static struct notifier_block ndisc_netdev_notifier = {
1940 .notifier_call = ndisc_netdev_event,
1941 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1942};
1943
1944#ifdef CONFIG_SYSCTL
1945static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl,
1946 const char *func, const char *dev_name)
1947{
1948 static char warncomm[TASK_COMM_LEN];
1949 static int warned;
1950 if (strcmp(warncomm, current->comm) && warned < 5) {
1951 strscpy(warncomm, current->comm);
1952 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1953 warncomm, func,
1954 dev_name, ctl->procname,
1955 dev_name, ctl->procname);
1956 warned++;
1957 }
1958}
1959
1960int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer,
1961 size_t *lenp, loff_t *ppos)
1962{
1963 struct net_device *dev = ctl->extra1;
1964 struct inet6_dev *idev;
1965 int ret;
1966
1967 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1968 (strcmp(ctl->procname, "base_reachable_time") == 0))
1969 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1970
1971 if (strcmp(ctl->procname, "retrans_time") == 0)
1972 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1973
1974 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1975 ret = neigh_proc_dointvec_jiffies(ctl, write,
1976 buffer, lenp, ppos);
1977
1978 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1979 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1980 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1981 buffer, lenp, ppos);
1982 else
1983 ret = -1;
1984
1985 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1986 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1987 idev->nd_parms->reachable_time =
1988 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1989 WRITE_ONCE(idev->tstamp, jiffies);
1990 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1991 in6_dev_put(idev);
1992 }
1993 return ret;
1994}
1995
1996
1997#endif
1998
1999static int __net_init ndisc_net_init(struct net *net)
2000{
2001 struct ipv6_pinfo *np;
2002 struct sock *sk;
2003 int err;
2004
2005 err = inet_ctl_sock_create(&sk, PF_INET6,
2006 SOCK_RAW, IPPROTO_ICMPV6, net);
2007 if (err < 0) {
2008 ND_PRINTK(0, err,
2009 "NDISC: Failed to initialize the control socket (err %d)\n",
2010 err);
2011 return err;
2012 }
2013
2014 net->ipv6.ndisc_sk = sk;
2015
2016 np = inet6_sk(sk);
2017 np->hop_limit = 255;
2018 /* Do not loopback ndisc messages */
2019 inet6_clear_bit(MC6_LOOP, sk);
2020
2021 return 0;
2022}
2023
2024static void __net_exit ndisc_net_exit(struct net *net)
2025{
2026 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
2027}
2028
2029static struct pernet_operations ndisc_net_ops = {
2030 .init = ndisc_net_init,
2031 .exit = ndisc_net_exit,
2032};
2033
2034int __init ndisc_init(void)
2035{
2036 int err;
2037
2038 err = register_pernet_subsys(&ndisc_net_ops);
2039 if (err)
2040 return err;
2041 /*
2042 * Initialize the neighbour table
2043 */
2044 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
2045
2046#ifdef CONFIG_SYSCTL
2047 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
2048 ndisc_ifinfo_sysctl_change);
2049 if (err)
2050 goto out_unregister_pernet;
2051out:
2052#endif
2053 return err;
2054
2055#ifdef CONFIG_SYSCTL
2056out_unregister_pernet:
2057 unregister_pernet_subsys(&ndisc_net_ops);
2058 goto out;
2059#endif
2060}
2061
2062int __init ndisc_late_init(void)
2063{
2064 return register_netdevice_notifier(&ndisc_netdev_notifier);
2065}
2066
2067void ndisc_late_cleanup(void)
2068{
2069 unregister_netdevice_notifier(&ndisc_netdev_notifier);
2070}
2071
2072void ndisc_cleanup(void)
2073{
2074#ifdef CONFIG_SYSCTL
2075 neigh_sysctl_unregister(&nd_tbl.parms);
2076#endif
2077 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
2078 unregister_pernet_subsys(&ndisc_net_ops);
2079}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Neighbour Discovery for IPv6
4 * Linux INET6 implementation
5 *
6 * Authors:
7 * Pedro Roque <roque@di.fc.ul.pt>
8 * Mike Shaver <shaver@ingenia.com>
9 */
10
11/*
12 * Changes:
13 *
14 * Alexey I. Froloff : RFC6106 (DNSSL) support
15 * Pierre Ynard : export userland ND options
16 * through netlink (RDNSS support)
17 * Lars Fenneberg : fixed MTU setting on receipt
18 * of an RA.
19 * Janos Farkas : kmalloc failure checks
20 * Alexey Kuznetsov : state machine reworked
21 * and moved to net/core.
22 * Pekka Savola : RFC2461 validation
23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
24 */
25
26#define pr_fmt(fmt) "ICMPv6: " fmt
27
28#include <linux/module.h>
29#include <linux/errno.h>
30#include <linux/types.h>
31#include <linux/socket.h>
32#include <linux/sockios.h>
33#include <linux/sched.h>
34#include <linux/net.h>
35#include <linux/in6.h>
36#include <linux/route.h>
37#include <linux/init.h>
38#include <linux/rcupdate.h>
39#include <linux/slab.h>
40#ifdef CONFIG_SYSCTL
41#include <linux/sysctl.h>
42#endif
43
44#include <linux/if_addr.h>
45#include <linux/if_ether.h>
46#include <linux/if_arp.h>
47#include <linux/ipv6.h>
48#include <linux/icmpv6.h>
49#include <linux/jhash.h>
50
51#include <net/sock.h>
52#include <net/snmp.h>
53
54#include <net/ipv6.h>
55#include <net/protocol.h>
56#include <net/ndisc.h>
57#include <net/ip6_route.h>
58#include <net/addrconf.h>
59#include <net/icmp.h>
60
61#include <net/netlink.h>
62#include <linux/rtnetlink.h>
63
64#include <net/flow.h>
65#include <net/ip6_checksum.h>
66#include <net/inet_common.h>
67#include <linux/proc_fs.h>
68
69#include <linux/netfilter.h>
70#include <linux/netfilter_ipv6.h>
71
72static u32 ndisc_hash(const void *pkey,
73 const struct net_device *dev,
74 __u32 *hash_rnd);
75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey);
76static bool ndisc_allow_add(const struct net_device *dev,
77 struct netlink_ext_ack *extack);
78static int ndisc_constructor(struct neighbour *neigh);
79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
81static int pndisc_constructor(struct pneigh_entry *n);
82static void pndisc_destructor(struct pneigh_entry *n);
83static void pndisc_redo(struct sk_buff *skb);
84static int ndisc_is_multicast(const void *pkey);
85
86static const struct neigh_ops ndisc_generic_ops = {
87 .family = AF_INET6,
88 .solicit = ndisc_solicit,
89 .error_report = ndisc_error_report,
90 .output = neigh_resolve_output,
91 .connected_output = neigh_connected_output,
92};
93
94static const struct neigh_ops ndisc_hh_ops = {
95 .family = AF_INET6,
96 .solicit = ndisc_solicit,
97 .error_report = ndisc_error_report,
98 .output = neigh_resolve_output,
99 .connected_output = neigh_resolve_output,
100};
101
102
103static const struct neigh_ops ndisc_direct_ops = {
104 .family = AF_INET6,
105 .output = neigh_direct_output,
106 .connected_output = neigh_direct_output,
107};
108
109struct neigh_table nd_tbl = {
110 .family = AF_INET6,
111 .key_len = sizeof(struct in6_addr),
112 .protocol = cpu_to_be16(ETH_P_IPV6),
113 .hash = ndisc_hash,
114 .key_eq = ndisc_key_eq,
115 .constructor = ndisc_constructor,
116 .pconstructor = pndisc_constructor,
117 .pdestructor = pndisc_destructor,
118 .proxy_redo = pndisc_redo,
119 .is_multicast = ndisc_is_multicast,
120 .allow_add = ndisc_allow_add,
121 .id = "ndisc_cache",
122 .parms = {
123 .tbl = &nd_tbl,
124 .reachable_time = ND_REACHABLE_TIME,
125 .data = {
126 [NEIGH_VAR_MCAST_PROBES] = 3,
127 [NEIGH_VAR_UCAST_PROBES] = 3,
128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER,
129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME,
130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
131 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
132 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX,
133 [NEIGH_VAR_PROXY_QLEN] = 64,
134 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
135 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
136 },
137 },
138 .gc_interval = 30 * HZ,
139 .gc_thresh1 = 128,
140 .gc_thresh2 = 512,
141 .gc_thresh3 = 1024,
142};
143EXPORT_SYMBOL_GPL(nd_tbl);
144
145void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
146 int data_len, int pad)
147{
148 int space = __ndisc_opt_addr_space(data_len, pad);
149 u8 *opt = skb_put(skb, space);
150
151 opt[0] = type;
152 opt[1] = space>>3;
153
154 memset(opt + 2, 0, pad);
155 opt += pad;
156 space -= pad;
157
158 memcpy(opt+2, data, data_len);
159 data_len += 2;
160 opt += data_len;
161 space -= data_len;
162 if (space > 0)
163 memset(opt, 0, space);
164}
165EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option);
166
167static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type,
168 void *data, u8 icmp6_type)
169{
170 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len,
171 ndisc_addr_option_pad(skb->dev->type));
172 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type);
173}
174
175static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb,
176 void *ha,
177 const u8 *ops_data)
178{
179 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT);
180 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data);
181}
182
183static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
184 struct nd_opt_hdr *end)
185{
186 int type;
187 if (!cur || !end || cur >= end)
188 return NULL;
189 type = cur->nd_opt_type;
190 do {
191 cur = ((void *)cur) + (cur->nd_opt_len << 3);
192 } while (cur < end && cur->nd_opt_type != type);
193 return cur <= end && cur->nd_opt_type == type ? cur : NULL;
194}
195
196static inline int ndisc_is_useropt(const struct net_device *dev,
197 struct nd_opt_hdr *opt)
198{
199 return opt->nd_opt_type == ND_OPT_RDNSS ||
200 opt->nd_opt_type == ND_OPT_DNSSL ||
201 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
202 opt->nd_opt_type == ND_OPT_PREF64 ||
203 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
204}
205
206static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev,
207 struct nd_opt_hdr *cur,
208 struct nd_opt_hdr *end)
209{
210 if (!cur || !end || cur >= end)
211 return NULL;
212 do {
213 cur = ((void *)cur) + (cur->nd_opt_len << 3);
214 } while (cur < end && !ndisc_is_useropt(dev, cur));
215 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL;
216}
217
218struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
219 u8 *opt, int opt_len,
220 struct ndisc_options *ndopts)
221{
222 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
223
224 if (!nd_opt || opt_len < 0 || !ndopts)
225 return NULL;
226 memset(ndopts, 0, sizeof(*ndopts));
227 while (opt_len) {
228 int l;
229 if (opt_len < sizeof(struct nd_opt_hdr))
230 return NULL;
231 l = nd_opt->nd_opt_len << 3;
232 if (opt_len < l || l == 0)
233 return NULL;
234 if (ndisc_ops_parse_options(dev, nd_opt, ndopts))
235 goto next_opt;
236 switch (nd_opt->nd_opt_type) {
237 case ND_OPT_SOURCE_LL_ADDR:
238 case ND_OPT_TARGET_LL_ADDR:
239 case ND_OPT_MTU:
240 case ND_OPT_NONCE:
241 case ND_OPT_REDIRECT_HDR:
242 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
243 ND_PRINTK(2, warn,
244 "%s: duplicated ND6 option found: type=%d\n",
245 __func__, nd_opt->nd_opt_type);
246 } else {
247 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
248 }
249 break;
250 case ND_OPT_PREFIX_INFO:
251 ndopts->nd_opts_pi_end = nd_opt;
252 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type])
253 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
254 break;
255#ifdef CONFIG_IPV6_ROUTE_INFO
256 case ND_OPT_ROUTE_INFO:
257 ndopts->nd_opts_ri_end = nd_opt;
258 if (!ndopts->nd_opts_ri)
259 ndopts->nd_opts_ri = nd_opt;
260 break;
261#endif
262 default:
263 if (ndisc_is_useropt(dev, nd_opt)) {
264 ndopts->nd_useropts_end = nd_opt;
265 if (!ndopts->nd_useropts)
266 ndopts->nd_useropts = nd_opt;
267 } else {
268 /*
269 * Unknown options must be silently ignored,
270 * to accommodate future extension to the
271 * protocol.
272 */
273 ND_PRINTK(2, notice,
274 "%s: ignored unsupported option; type=%d, len=%d\n",
275 __func__,
276 nd_opt->nd_opt_type,
277 nd_opt->nd_opt_len);
278 }
279 }
280next_opt:
281 opt_len -= l;
282 nd_opt = ((void *)nd_opt) + l;
283 }
284 return ndopts;
285}
286
287int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
288{
289 switch (dev->type) {
290 case ARPHRD_ETHER:
291 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
292 case ARPHRD_FDDI:
293 ipv6_eth_mc_map(addr, buf);
294 return 0;
295 case ARPHRD_ARCNET:
296 ipv6_arcnet_mc_map(addr, buf);
297 return 0;
298 case ARPHRD_INFINIBAND:
299 ipv6_ib_mc_map(addr, dev->broadcast, buf);
300 return 0;
301 case ARPHRD_IPGRE:
302 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf);
303 default:
304 if (dir) {
305 memcpy(buf, dev->broadcast, dev->addr_len);
306 return 0;
307 }
308 }
309 return -EINVAL;
310}
311EXPORT_SYMBOL(ndisc_mc_map);
312
313static u32 ndisc_hash(const void *pkey,
314 const struct net_device *dev,
315 __u32 *hash_rnd)
316{
317 return ndisc_hashfn(pkey, dev, hash_rnd);
318}
319
320static bool ndisc_key_eq(const struct neighbour *n, const void *pkey)
321{
322 return neigh_key_eq128(n, pkey);
323}
324
325static int ndisc_constructor(struct neighbour *neigh)
326{
327 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key;
328 struct net_device *dev = neigh->dev;
329 struct inet6_dev *in6_dev;
330 struct neigh_parms *parms;
331 bool is_multicast = ipv6_addr_is_multicast(addr);
332
333 in6_dev = in6_dev_get(dev);
334 if (!in6_dev) {
335 return -EINVAL;
336 }
337
338 parms = in6_dev->nd_parms;
339 __neigh_parms_put(neigh->parms);
340 neigh->parms = neigh_parms_clone(parms);
341
342 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST;
343 if (!dev->header_ops) {
344 neigh->nud_state = NUD_NOARP;
345 neigh->ops = &ndisc_direct_ops;
346 neigh->output = neigh_direct_output;
347 } else {
348 if (is_multicast) {
349 neigh->nud_state = NUD_NOARP;
350 ndisc_mc_map(addr, neigh->ha, dev, 1);
351 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
352 neigh->nud_state = NUD_NOARP;
353 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
354 if (dev->flags&IFF_LOOPBACK)
355 neigh->type = RTN_LOCAL;
356 } else if (dev->flags&IFF_POINTOPOINT) {
357 neigh->nud_state = NUD_NOARP;
358 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
359 }
360 if (dev->header_ops->cache)
361 neigh->ops = &ndisc_hh_ops;
362 else
363 neigh->ops = &ndisc_generic_ops;
364 if (neigh->nud_state&NUD_VALID)
365 neigh->output = neigh->ops->connected_output;
366 else
367 neigh->output = neigh->ops->output;
368 }
369 in6_dev_put(in6_dev);
370 return 0;
371}
372
373static int pndisc_constructor(struct pneigh_entry *n)
374{
375 struct in6_addr *addr = (struct in6_addr *)&n->key;
376 struct in6_addr maddr;
377 struct net_device *dev = n->dev;
378
379 if (!dev || !__in6_dev_get(dev))
380 return -EINVAL;
381 addrconf_addr_solict_mult(addr, &maddr);
382 ipv6_dev_mc_inc(dev, &maddr);
383 return 0;
384}
385
386static void pndisc_destructor(struct pneigh_entry *n)
387{
388 struct in6_addr *addr = (struct in6_addr *)&n->key;
389 struct in6_addr maddr;
390 struct net_device *dev = n->dev;
391
392 if (!dev || !__in6_dev_get(dev))
393 return;
394 addrconf_addr_solict_mult(addr, &maddr);
395 ipv6_dev_mc_dec(dev, &maddr);
396}
397
398/* called with rtnl held */
399static bool ndisc_allow_add(const struct net_device *dev,
400 struct netlink_ext_ack *extack)
401{
402 struct inet6_dev *idev = __in6_dev_get(dev);
403
404 if (!idev || idev->cnf.disable_ipv6) {
405 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device");
406 return false;
407 }
408
409 return true;
410}
411
412static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
413 int len)
414{
415 int hlen = LL_RESERVED_SPACE(dev);
416 int tlen = dev->needed_tailroom;
417 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
418 struct sk_buff *skb;
419
420 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
421 if (!skb) {
422 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
423 __func__);
424 return NULL;
425 }
426
427 skb->protocol = htons(ETH_P_IPV6);
428 skb->dev = dev;
429
430 skb_reserve(skb, hlen + sizeof(struct ipv6hdr));
431 skb_reset_transport_header(skb);
432
433 /* Manually assign socket ownership as we avoid calling
434 * sock_alloc_send_pskb() to bypass wmem buffer limits
435 */
436 skb_set_owner_w(skb, sk);
437
438 return skb;
439}
440
441static void ip6_nd_hdr(struct sk_buff *skb,
442 const struct in6_addr *saddr,
443 const struct in6_addr *daddr,
444 int hop_limit, int len)
445{
446 struct ipv6hdr *hdr;
447 struct inet6_dev *idev;
448 unsigned tclass;
449
450 rcu_read_lock();
451 idev = __in6_dev_get(skb->dev);
452 tclass = idev ? idev->cnf.ndisc_tclass : 0;
453 rcu_read_unlock();
454
455 skb_push(skb, sizeof(*hdr));
456 skb_reset_network_header(skb);
457 hdr = ipv6_hdr(skb);
458
459 ip6_flow_hdr(hdr, tclass, 0);
460
461 hdr->payload_len = htons(len);
462 hdr->nexthdr = IPPROTO_ICMPV6;
463 hdr->hop_limit = hop_limit;
464
465 hdr->saddr = *saddr;
466 hdr->daddr = *daddr;
467}
468
469static void ndisc_send_skb(struct sk_buff *skb,
470 const struct in6_addr *daddr,
471 const struct in6_addr *saddr)
472{
473 struct dst_entry *dst = skb_dst(skb);
474 struct net *net = dev_net(skb->dev);
475 struct sock *sk = net->ipv6.ndisc_sk;
476 struct inet6_dev *idev;
477 int err;
478 struct icmp6hdr *icmp6h = icmp6_hdr(skb);
479 u8 type;
480
481 type = icmp6h->icmp6_type;
482
483 if (!dst) {
484 struct flowi6 fl6;
485 int oif = skb->dev->ifindex;
486
487 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif);
488 dst = icmp6_dst_alloc(skb->dev, &fl6);
489 if (IS_ERR(dst)) {
490 kfree_skb(skb);
491 return;
492 }
493
494 skb_dst_set(skb, dst);
495 }
496
497 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len,
498 IPPROTO_ICMPV6,
499 csum_partial(icmp6h,
500 skb->len, 0));
501
502 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len);
503
504 rcu_read_lock();
505 idev = __in6_dev_get(dst->dev);
506 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
507
508 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
509 net, sk, skb, NULL, dst->dev,
510 dst_output);
511 if (!err) {
512 ICMP6MSGOUT_INC_STATS(net, idev, type);
513 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
514 }
515
516 rcu_read_unlock();
517}
518
519void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
520 const struct in6_addr *solicited_addr,
521 bool router, bool solicited, bool override, bool inc_opt)
522{
523 struct sk_buff *skb;
524 struct in6_addr tmpaddr;
525 struct inet6_ifaddr *ifp;
526 const struct in6_addr *src_addr;
527 struct nd_msg *msg;
528 int optlen = 0;
529
530 /* for anycast or proxy, solicited_addr != src_addr */
531 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
532 if (ifp) {
533 src_addr = solicited_addr;
534 if (ifp->flags & IFA_F_OPTIMISTIC)
535 override = false;
536 inc_opt |= ifp->idev->cnf.force_tllao;
537 in6_ifa_put(ifp);
538 } else {
539 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr,
540 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs,
541 &tmpaddr))
542 return;
543 src_addr = &tmpaddr;
544 }
545
546 if (!dev->addr_len)
547 inc_opt = false;
548 if (inc_opt)
549 optlen += ndisc_opt_addr_space(dev,
550 NDISC_NEIGHBOUR_ADVERTISEMENT);
551
552 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
553 if (!skb)
554 return;
555
556 msg = skb_put(skb, sizeof(*msg));
557 *msg = (struct nd_msg) {
558 .icmph = {
559 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
560 .icmp6_router = router,
561 .icmp6_solicited = solicited,
562 .icmp6_override = override,
563 },
564 .target = *solicited_addr,
565 };
566
567 if (inc_opt)
568 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
569 dev->dev_addr,
570 NDISC_NEIGHBOUR_ADVERTISEMENT);
571
572 ndisc_send_skb(skb, daddr, src_addr);
573}
574
575static void ndisc_send_unsol_na(struct net_device *dev)
576{
577 struct inet6_dev *idev;
578 struct inet6_ifaddr *ifa;
579
580 idev = in6_dev_get(dev);
581 if (!idev)
582 return;
583
584 read_lock_bh(&idev->lock);
585 list_for_each_entry(ifa, &idev->addr_list, if_list) {
586 /* skip tentative addresses until dad completes */
587 if (ifa->flags & IFA_F_TENTATIVE &&
588 !(ifa->flags & IFA_F_OPTIMISTIC))
589 continue;
590
591 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr,
592 /*router=*/ !!idev->cnf.forwarding,
593 /*solicited=*/ false, /*override=*/ true,
594 /*inc_opt=*/ true);
595 }
596 read_unlock_bh(&idev->lock);
597
598 in6_dev_put(idev);
599}
600
601void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
602 const struct in6_addr *daddr, const struct in6_addr *saddr,
603 u64 nonce)
604{
605 struct sk_buff *skb;
606 struct in6_addr addr_buf;
607 int inc_opt = dev->addr_len;
608 int optlen = 0;
609 struct nd_msg *msg;
610
611 if (!saddr) {
612 if (ipv6_get_lladdr(dev, &addr_buf,
613 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
614 return;
615 saddr = &addr_buf;
616 }
617
618 if (ipv6_addr_any(saddr))
619 inc_opt = false;
620 if (inc_opt)
621 optlen += ndisc_opt_addr_space(dev,
622 NDISC_NEIGHBOUR_SOLICITATION);
623 if (nonce != 0)
624 optlen += 8;
625
626 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
627 if (!skb)
628 return;
629
630 msg = skb_put(skb, sizeof(*msg));
631 *msg = (struct nd_msg) {
632 .icmph = {
633 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
634 },
635 .target = *solicit,
636 };
637
638 if (inc_opt)
639 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
640 dev->dev_addr,
641 NDISC_NEIGHBOUR_SOLICITATION);
642 if (nonce != 0) {
643 u8 *opt = skb_put(skb, 8);
644
645 opt[0] = ND_OPT_NONCE;
646 opt[1] = 8 >> 3;
647 memcpy(opt + 2, &nonce, 6);
648 }
649
650 ndisc_send_skb(skb, daddr, saddr);
651}
652
653void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
654 const struct in6_addr *daddr)
655{
656 struct sk_buff *skb;
657 struct rs_msg *msg;
658 int send_sllao = dev->addr_len;
659 int optlen = 0;
660
661#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
662 /*
663 * According to section 2.2 of RFC 4429, we must not
664 * send router solicitations with a sllao from
665 * optimistic addresses, but we may send the solicitation
666 * if we don't include the sllao. So here we check
667 * if our address is optimistic, and if so, we
668 * suppress the inclusion of the sllao.
669 */
670 if (send_sllao) {
671 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr,
672 dev, 1);
673 if (ifp) {
674 if (ifp->flags & IFA_F_OPTIMISTIC) {
675 send_sllao = 0;
676 }
677 in6_ifa_put(ifp);
678 } else {
679 send_sllao = 0;
680 }
681 }
682#endif
683 if (send_sllao)
684 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION);
685
686 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
687 if (!skb)
688 return;
689
690 msg = skb_put(skb, sizeof(*msg));
691 *msg = (struct rs_msg) {
692 .icmph = {
693 .icmp6_type = NDISC_ROUTER_SOLICITATION,
694 },
695 };
696
697 if (send_sllao)
698 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
699 dev->dev_addr,
700 NDISC_ROUTER_SOLICITATION);
701
702 ndisc_send_skb(skb, daddr, saddr);
703}
704
705
706static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
707{
708 /*
709 * "The sender MUST return an ICMP
710 * destination unreachable"
711 */
712 dst_link_failure(skb);
713 kfree_skb(skb);
714}
715
716/* Called with locked neigh: either read or both */
717
718static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
719{
720 struct in6_addr *saddr = NULL;
721 struct in6_addr mcaddr;
722 struct net_device *dev = neigh->dev;
723 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
724 int probes = atomic_read(&neigh->probes);
725
726 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr,
727 dev, false, 1,
728 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))
729 saddr = &ipv6_hdr(skb)->saddr;
730 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
731 if (probes < 0) {
732 if (!(neigh->nud_state & NUD_VALID)) {
733 ND_PRINTK(1, dbg,
734 "%s: trying to ucast probe in NUD_INVALID: %pI6\n",
735 __func__, target);
736 }
737 ndisc_send_ns(dev, target, target, saddr, 0);
738 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) {
739 neigh_app_ns(neigh);
740 } else {
741 addrconf_addr_solict_mult(target, &mcaddr);
742 ndisc_send_ns(dev, target, &mcaddr, saddr, 0);
743 }
744}
745
746static int pndisc_is_router(const void *pkey,
747 struct net_device *dev)
748{
749 struct pneigh_entry *n;
750 int ret = -1;
751
752 read_lock_bh(&nd_tbl.lock);
753 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev);
754 if (n)
755 ret = !!(n->flags & NTF_ROUTER);
756 read_unlock_bh(&nd_tbl.lock);
757
758 return ret;
759}
760
761void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
762 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
763 struct ndisc_options *ndopts)
764{
765 neigh_update(neigh, lladdr, new, flags, 0);
766 /* report ndisc ops about neighbour update */
767 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
768}
769
770static void ndisc_recv_ns(struct sk_buff *skb)
771{
772 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
773 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
774 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
775 u8 *lladdr = NULL;
776 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
777 offsetof(struct nd_msg, opt));
778 struct ndisc_options ndopts;
779 struct net_device *dev = skb->dev;
780 struct inet6_ifaddr *ifp;
781 struct inet6_dev *idev = NULL;
782 struct neighbour *neigh;
783 int dad = ipv6_addr_any(saddr);
784 bool inc;
785 int is_router = -1;
786 u64 nonce = 0;
787
788 if (skb->len < sizeof(struct nd_msg)) {
789 ND_PRINTK(2, warn, "NS: packet too short\n");
790 return;
791 }
792
793 if (ipv6_addr_is_multicast(&msg->target)) {
794 ND_PRINTK(2, warn, "NS: multicast target address\n");
795 return;
796 }
797
798 /*
799 * RFC2461 7.1.1:
800 * DAD has to be destined for solicited node multicast address.
801 */
802 if (dad && !ipv6_addr_is_solict_mult(daddr)) {
803 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
804 return;
805 }
806
807 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
808 ND_PRINTK(2, warn, "NS: invalid ND options\n");
809 return;
810 }
811
812 if (ndopts.nd_opts_src_lladdr) {
813 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
814 if (!lladdr) {
815 ND_PRINTK(2, warn,
816 "NS: invalid link-layer address length\n");
817 return;
818 }
819
820 /* RFC2461 7.1.1:
821 * If the IP source address is the unspecified address,
822 * there MUST NOT be source link-layer address option
823 * in the message.
824 */
825 if (dad) {
826 ND_PRINTK(2, warn,
827 "NS: bad DAD packet (link-layer address option)\n");
828 return;
829 }
830 }
831 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
832 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6);
833
834 inc = ipv6_addr_is_multicast(daddr);
835
836 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
837 if (ifp) {
838have_ifp:
839 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
840 if (dad) {
841 if (nonce != 0 && ifp->dad_nonce == nonce) {
842 u8 *np = (u8 *)&nonce;
843 /* Matching nonce if looped back */
844 ND_PRINTK(2, notice,
845 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n",
846 ifp->idev->dev->name,
847 &ifp->addr, np);
848 goto out;
849 }
850 /*
851 * We are colliding with another node
852 * who is doing DAD
853 * so fail our DAD process
854 */
855 addrconf_dad_failure(skb, ifp);
856 return;
857 } else {
858 /*
859 * This is not a dad solicitation.
860 * If we are an optimistic node,
861 * we should respond.
862 * Otherwise, we should ignore it.
863 */
864 if (!(ifp->flags & IFA_F_OPTIMISTIC))
865 goto out;
866 }
867 }
868
869 idev = ifp->idev;
870 } else {
871 struct net *net = dev_net(dev);
872
873 /* perhaps an address on the master device */
874 if (netif_is_l3_slave(dev)) {
875 struct net_device *mdev;
876
877 mdev = netdev_master_upper_dev_get_rcu(dev);
878 if (mdev) {
879 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1);
880 if (ifp)
881 goto have_ifp;
882 }
883 }
884
885 idev = in6_dev_get(dev);
886 if (!idev) {
887 /* XXX: count this drop? */
888 return;
889 }
890
891 if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
892 (idev->cnf.forwarding &&
893 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
894 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
895 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
896 skb->pkt_type != PACKET_HOST &&
897 inc &&
898 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) {
899 /*
900 * for anycast or proxy,
901 * sender should delay its response
902 * by a random time between 0 and
903 * MAX_ANYCAST_DELAY_TIME seconds.
904 * (RFC2461) -- yoshfuji
905 */
906 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
907 if (n)
908 pneigh_enqueue(&nd_tbl, idev->nd_parms, n);
909 goto out;
910 }
911 } else
912 goto out;
913 }
914
915 if (is_router < 0)
916 is_router = idev->cnf.forwarding;
917
918 if (dad) {
919 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target,
920 !!is_router, false, (ifp != NULL), true);
921 goto out;
922 }
923
924 if (inc)
925 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast);
926 else
927 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast);
928
929 /*
930 * update / create cache entry
931 * for the source address
932 */
933 neigh = __neigh_lookup(&nd_tbl, saddr, dev,
934 !inc || lladdr || !dev->addr_len);
935 if (neigh)
936 ndisc_update(dev, neigh, lladdr, NUD_STALE,
937 NEIGH_UPDATE_F_WEAK_OVERRIDE|
938 NEIGH_UPDATE_F_OVERRIDE,
939 NDISC_NEIGHBOUR_SOLICITATION, &ndopts);
940 if (neigh || !dev->header_ops) {
941 ndisc_send_na(dev, saddr, &msg->target, !!is_router,
942 true, (ifp != NULL && inc), inc);
943 if (neigh)
944 neigh_release(neigh);
945 }
946
947out:
948 if (ifp)
949 in6_ifa_put(ifp);
950 else
951 in6_dev_put(idev);
952}
953
954static void ndisc_recv_na(struct sk_buff *skb)
955{
956 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
957 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
958 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
959 u8 *lladdr = NULL;
960 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
961 offsetof(struct nd_msg, opt));
962 struct ndisc_options ndopts;
963 struct net_device *dev = skb->dev;
964 struct inet6_dev *idev = __in6_dev_get(dev);
965 struct inet6_ifaddr *ifp;
966 struct neighbour *neigh;
967
968 if (skb->len < sizeof(struct nd_msg)) {
969 ND_PRINTK(2, warn, "NA: packet too short\n");
970 return;
971 }
972
973 if (ipv6_addr_is_multicast(&msg->target)) {
974 ND_PRINTK(2, warn, "NA: target address is multicast\n");
975 return;
976 }
977
978 if (ipv6_addr_is_multicast(daddr) &&
979 msg->icmph.icmp6_solicited) {
980 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
981 return;
982 }
983
984 /* For some 802.11 wireless deployments (and possibly other networks),
985 * there will be a NA proxy and unsolicitd packets are attacks
986 * and thus should not be accepted.
987 */
988 if (!msg->icmph.icmp6_solicited && idev &&
989 idev->cnf.drop_unsolicited_na)
990 return;
991
992 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
993 ND_PRINTK(2, warn, "NS: invalid ND option\n");
994 return;
995 }
996 if (ndopts.nd_opts_tgt_lladdr) {
997 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
998 if (!lladdr) {
999 ND_PRINTK(2, warn,
1000 "NA: invalid link-layer address length\n");
1001 return;
1002 }
1003 }
1004 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
1005 if (ifp) {
1006 if (skb->pkt_type != PACKET_LOOPBACK
1007 && (ifp->flags & IFA_F_TENTATIVE)) {
1008 addrconf_dad_failure(skb, ifp);
1009 return;
1010 }
1011 /* What should we make now? The advertisement
1012 is invalid, but ndisc specs say nothing
1013 about it. It could be misconfiguration, or
1014 an smart proxy agent tries to help us :-)
1015
1016 We should not print the error if NA has been
1017 received from loopback - it is just our own
1018 unsolicited advertisement.
1019 */
1020 if (skb->pkt_type != PACKET_LOOPBACK)
1021 ND_PRINTK(1, warn,
1022 "NA: %pM advertised our address %pI6c on %s!\n",
1023 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
1024 in6_ifa_put(ifp);
1025 return;
1026 }
1027 neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
1028
1029 if (neigh) {
1030 u8 old_flags = neigh->flags;
1031 struct net *net = dev_net(dev);
1032
1033 if (neigh->nud_state & NUD_FAILED)
1034 goto out;
1035
1036 /*
1037 * Don't update the neighbor cache entry on a proxy NA from
1038 * ourselves because either the proxied node is off link or it
1039 * has already sent a NA to us.
1040 */
1041 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
1042 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp &&
1043 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
1044 /* XXX: idev->cnf.proxy_ndp */
1045 goto out;
1046 }
1047
1048 ndisc_update(dev, neigh, lladdr,
1049 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
1050 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1051 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)|
1052 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1053 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0),
1054 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts);
1055
1056 if ((old_flags & ~neigh->flags) & NTF_ROUTER) {
1057 /*
1058 * Change: router to host
1059 */
1060 rt6_clean_tohost(dev_net(dev), saddr);
1061 }
1062
1063out:
1064 neigh_release(neigh);
1065 }
1066}
1067
1068static void ndisc_recv_rs(struct sk_buff *skb)
1069{
1070 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb);
1071 unsigned long ndoptlen = skb->len - sizeof(*rs_msg);
1072 struct neighbour *neigh;
1073 struct inet6_dev *idev;
1074 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
1075 struct ndisc_options ndopts;
1076 u8 *lladdr = NULL;
1077
1078 if (skb->len < sizeof(*rs_msg))
1079 return;
1080
1081 idev = __in6_dev_get(skb->dev);
1082 if (!idev) {
1083 ND_PRINTK(1, err, "RS: can't find in6 device\n");
1084 return;
1085 }
1086
1087 /* Don't accept RS if we're not in router mode */
1088 if (!idev->cnf.forwarding)
1089 goto out;
1090
1091 /*
1092 * Don't update NCE if src = ::;
1093 * this implies that the source node has no ip address assigned yet.
1094 */
1095 if (ipv6_addr_any(saddr))
1096 goto out;
1097
1098 /* Parse ND options */
1099 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
1100 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
1101 goto out;
1102 }
1103
1104 if (ndopts.nd_opts_src_lladdr) {
1105 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1106 skb->dev);
1107 if (!lladdr)
1108 goto out;
1109 }
1110
1111 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1);
1112 if (neigh) {
1113 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1114 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1115 NEIGH_UPDATE_F_OVERRIDE|
1116 NEIGH_UPDATE_F_OVERRIDE_ISROUTER,
1117 NDISC_ROUTER_SOLICITATION, &ndopts);
1118 neigh_release(neigh);
1119 }
1120out:
1121 return;
1122}
1123
1124static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
1125{
1126 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
1127 struct sk_buff *skb;
1128 struct nlmsghdr *nlh;
1129 struct nduseroptmsg *ndmsg;
1130 struct net *net = dev_net(ra->dev);
1131 int err;
1132 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
1133 + (opt->nd_opt_len << 3));
1134 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
1135
1136 skb = nlmsg_new(msg_size, GFP_ATOMIC);
1137 if (!skb) {
1138 err = -ENOBUFS;
1139 goto errout;
1140 }
1141
1142 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
1143 if (!nlh) {
1144 goto nla_put_failure;
1145 }
1146
1147 ndmsg = nlmsg_data(nlh);
1148 ndmsg->nduseropt_family = AF_INET6;
1149 ndmsg->nduseropt_ifindex = ra->dev->ifindex;
1150 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
1151 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
1152 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
1153
1154 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
1155
1156 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr))
1157 goto nla_put_failure;
1158 nlmsg_end(skb, nlh);
1159
1160 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC);
1161 return;
1162
1163nla_put_failure:
1164 nlmsg_free(skb);
1165 err = -EMSGSIZE;
1166errout:
1167 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
1168}
1169
1170static void ndisc_router_discovery(struct sk_buff *skb)
1171{
1172 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb);
1173 struct neighbour *neigh = NULL;
1174 struct inet6_dev *in6_dev;
1175 struct fib6_info *rt = NULL;
1176 u32 defrtr_usr_metric;
1177 struct net *net;
1178 int lifetime;
1179 struct ndisc_options ndopts;
1180 int optlen;
1181 unsigned int pref = 0;
1182 __u32 old_if_flags;
1183 bool send_ifinfo_notify = false;
1184
1185 __u8 *opt = (__u8 *)(ra_msg + 1);
1186
1187 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) -
1188 sizeof(struct ra_msg);
1189
1190 ND_PRINTK(2, info,
1191 "RA: %s, dev: %s\n",
1192 __func__, skb->dev->name);
1193 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1194 ND_PRINTK(2, warn, "RA: source address is not link-local\n");
1195 return;
1196 }
1197 if (optlen < 0) {
1198 ND_PRINTK(2, warn, "RA: packet too short\n");
1199 return;
1200 }
1201
1202#ifdef CONFIG_IPV6_NDISC_NODETYPE
1203 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) {
1204 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n");
1205 return;
1206 }
1207#endif
1208
1209 /*
1210 * set the RA_RECV flag in the interface
1211 */
1212
1213 in6_dev = __in6_dev_get(skb->dev);
1214 if (!in6_dev) {
1215 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n",
1216 skb->dev->name);
1217 return;
1218 }
1219
1220 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
1221 ND_PRINTK(2, warn, "RA: invalid ND options\n");
1222 return;
1223 }
1224
1225 if (!ipv6_accept_ra(in6_dev)) {
1226 ND_PRINTK(2, info,
1227 "RA: %s, did not accept ra for dev: %s\n",
1228 __func__, skb->dev->name);
1229 goto skip_linkparms;
1230 }
1231
1232#ifdef CONFIG_IPV6_NDISC_NODETYPE
1233 /* skip link-specific parameters from interior routers */
1234 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1235 ND_PRINTK(2, info,
1236 "RA: %s, nodetype is NODEFAULT, dev: %s\n",
1237 __func__, skb->dev->name);
1238 goto skip_linkparms;
1239 }
1240#endif
1241
1242 if (in6_dev->if_flags & IF_RS_SENT) {
1243 /*
1244 * flag that an RA was received after an RS was sent
1245 * out on this interface.
1246 */
1247 in6_dev->if_flags |= IF_RA_RCVD;
1248 }
1249
1250 /*
1251 * Remember the managed/otherconf flags from most recently
1252 * received RA message (RFC 2462) -- yoshfuji
1253 */
1254 old_if_flags = in6_dev->if_flags;
1255 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED |
1256 IF_RA_OTHERCONF)) |
1257 (ra_msg->icmph.icmp6_addrconf_managed ?
1258 IF_RA_MANAGED : 0) |
1259 (ra_msg->icmph.icmp6_addrconf_other ?
1260 IF_RA_OTHERCONF : 0);
1261
1262 if (old_if_flags != in6_dev->if_flags)
1263 send_ifinfo_notify = true;
1264
1265 if (!in6_dev->cnf.accept_ra_defrtr) {
1266 ND_PRINTK(2, info,
1267 "RA: %s, defrtr is false for dev: %s\n",
1268 __func__, skb->dev->name);
1269 goto skip_defrtr;
1270 }
1271
1272 /* Do not accept RA with source-addr found on local machine unless
1273 * accept_ra_from_local is set to true.
1274 */
1275 net = dev_net(in6_dev->dev);
1276 if (!in6_dev->cnf.accept_ra_from_local &&
1277 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) {
1278 ND_PRINTK(2, info,
1279 "RA from local address detected on dev: %s: default router ignored\n",
1280 skb->dev->name);
1281 goto skip_defrtr;
1282 }
1283
1284 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
1285
1286#ifdef CONFIG_IPV6_ROUTER_PREF
1287 pref = ra_msg->icmph.icmp6_router_pref;
1288 /* 10b is handled as if it were 00b (medium) */
1289 if (pref == ICMPV6_ROUTER_PREF_INVALID ||
1290 !in6_dev->cnf.accept_ra_rtr_pref)
1291 pref = ICMPV6_ROUTER_PREF_MEDIUM;
1292#endif
1293 /* routes added from RAs do not use nexthop objects */
1294 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
1295 if (rt) {
1296 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1297 rt->fib6_nh->fib_nh_dev, NULL,
1298 &ipv6_hdr(skb)->saddr);
1299 if (!neigh) {
1300 ND_PRINTK(0, err,
1301 "RA: %s got default router without neighbour\n",
1302 __func__);
1303 fib6_info_release(rt);
1304 return;
1305 }
1306 }
1307 /* Set default route metric as specified by user */
1308 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric;
1309 /* delete the route if lifetime is 0 or if metric needs change */
1310 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) {
1311 ip6_del_rt(net, rt, false);
1312 rt = NULL;
1313 }
1314
1315 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
1316 rt, lifetime, defrtr_usr_metric, skb->dev->name);
1317 if (!rt && lifetime) {
1318 ND_PRINTK(3, info, "RA: adding default router\n");
1319
1320 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
1321 skb->dev, pref, defrtr_usr_metric);
1322 if (!rt) {
1323 ND_PRINTK(0, err,
1324 "RA: %s failed to add default route\n",
1325 __func__);
1326 return;
1327 }
1328
1329 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
1330 rt->fib6_nh->fib_nh_dev, NULL,
1331 &ipv6_hdr(skb)->saddr);
1332 if (!neigh) {
1333 ND_PRINTK(0, err,
1334 "RA: %s got default router without neighbour\n",
1335 __func__);
1336 fib6_info_release(rt);
1337 return;
1338 }
1339 neigh->flags |= NTF_ROUTER;
1340 } else if (rt) {
1341 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
1342 }
1343
1344 if (rt)
1345 fib6_set_expires(rt, jiffies + (HZ * lifetime));
1346 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 &&
1347 ra_msg->icmph.icmp6_hop_limit) {
1348 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) {
1349 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
1350 fib6_metric_set(rt, RTAX_HOPLIMIT,
1351 ra_msg->icmph.icmp6_hop_limit);
1352 } else {
1353 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n");
1354 }
1355 }
1356
1357skip_defrtr:
1358
1359 /*
1360 * Update Reachable Time and Retrans Timer
1361 */
1362
1363 if (in6_dev->nd_parms) {
1364 unsigned long rtime = ntohl(ra_msg->retrans_timer);
1365
1366 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
1367 rtime = (rtime*HZ)/1000;
1368 if (rtime < HZ/100)
1369 rtime = HZ/100;
1370 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
1371 in6_dev->tstamp = jiffies;
1372 send_ifinfo_notify = true;
1373 }
1374
1375 rtime = ntohl(ra_msg->reachable_time);
1376 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
1377 rtime = (rtime*HZ)/1000;
1378
1379 if (rtime < HZ/10)
1380 rtime = HZ/10;
1381
1382 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) {
1383 NEIGH_VAR_SET(in6_dev->nd_parms,
1384 BASE_REACHABLE_TIME, rtime);
1385 NEIGH_VAR_SET(in6_dev->nd_parms,
1386 GC_STALETIME, 3 * rtime);
1387 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
1388 in6_dev->tstamp = jiffies;
1389 send_ifinfo_notify = true;
1390 }
1391 }
1392 }
1393
1394 /*
1395 * Send a notify if RA changed managed/otherconf flags or timer settings
1396 */
1397 if (send_ifinfo_notify)
1398 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev);
1399
1400skip_linkparms:
1401
1402 /*
1403 * Process options.
1404 */
1405
1406 if (!neigh)
1407 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr,
1408 skb->dev, 1);
1409 if (neigh) {
1410 u8 *lladdr = NULL;
1411 if (ndopts.nd_opts_src_lladdr) {
1412 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
1413 skb->dev);
1414 if (!lladdr) {
1415 ND_PRINTK(2, warn,
1416 "RA: invalid link-layer address length\n");
1417 goto out;
1418 }
1419 }
1420 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
1421 NEIGH_UPDATE_F_WEAK_OVERRIDE|
1422 NEIGH_UPDATE_F_OVERRIDE|
1423 NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1424 NEIGH_UPDATE_F_ISROUTER,
1425 NDISC_ROUTER_ADVERTISEMENT, &ndopts);
1426 }
1427
1428 if (!ipv6_accept_ra(in6_dev)) {
1429 ND_PRINTK(2, info,
1430 "RA: %s, accept_ra is false for dev: %s\n",
1431 __func__, skb->dev->name);
1432 goto out;
1433 }
1434
1435#ifdef CONFIG_IPV6_ROUTE_INFO
1436 if (!in6_dev->cnf.accept_ra_from_local &&
1437 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,
1438 in6_dev->dev, 0)) {
1439 ND_PRINTK(2, info,
1440 "RA from local address detected on dev: %s: router info ignored.\n",
1441 skb->dev->name);
1442 goto skip_routeinfo;
1443 }
1444
1445 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) {
1446 struct nd_opt_hdr *p;
1447 for (p = ndopts.nd_opts_ri;
1448 p;
1449 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) {
1450 struct route_info *ri = (struct route_info *)p;
1451#ifdef CONFIG_IPV6_NDISC_NODETYPE
1452 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT &&
1453 ri->prefix_len == 0)
1454 continue;
1455#endif
1456 if (ri->prefix_len == 0 &&
1457 !in6_dev->cnf.accept_ra_defrtr)
1458 continue;
1459 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
1460 continue;
1461 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
1462 continue;
1463 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,
1464 &ipv6_hdr(skb)->saddr);
1465 }
1466 }
1467
1468skip_routeinfo:
1469#endif
1470
1471#ifdef CONFIG_IPV6_NDISC_NODETYPE
1472 /* skip link-specific ndopts from interior routers */
1473 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
1474 ND_PRINTK(2, info,
1475 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n",
1476 __func__, skb->dev->name);
1477 goto out;
1478 }
1479#endif
1480
1481 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) {
1482 struct nd_opt_hdr *p;
1483 for (p = ndopts.nd_opts_pi;
1484 p;
1485 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
1486 addrconf_prefix_rcv(skb->dev, (u8 *)p,
1487 (p->nd_opt_len) << 3,
1488 ndopts.nd_opts_src_lladdr != NULL);
1489 }
1490 }
1491
1492 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) {
1493 __be32 n;
1494 u32 mtu;
1495
1496 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
1497 mtu = ntohl(n);
1498
1499 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
1500 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu);
1501 } else if (in6_dev->cnf.mtu6 != mtu) {
1502 in6_dev->cnf.mtu6 = mtu;
1503 fib6_metric_set(rt, RTAX_MTU, mtu);
1504 rt6_mtu_change(skb->dev, mtu);
1505 }
1506 }
1507
1508 if (ndopts.nd_useropts) {
1509 struct nd_opt_hdr *p;
1510 for (p = ndopts.nd_useropts;
1511 p;
1512 p = ndisc_next_useropt(skb->dev, p,
1513 ndopts.nd_useropts_end)) {
1514 ndisc_ra_useropt(skb, p);
1515 }
1516 }
1517
1518 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
1519 ND_PRINTK(2, warn, "RA: invalid RA options\n");
1520 }
1521out:
1522 fib6_info_release(rt);
1523 if (neigh)
1524 neigh_release(neigh);
1525}
1526
1527static void ndisc_redirect_rcv(struct sk_buff *skb)
1528{
1529 u8 *hdr;
1530 struct ndisc_options ndopts;
1531 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb);
1532 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
1533 offsetof(struct rd_msg, opt));
1534
1535#ifdef CONFIG_IPV6_NDISC_NODETYPE
1536 switch (skb->ndisc_nodetype) {
1537 case NDISC_NODETYPE_HOST:
1538 case NDISC_NODETYPE_NODEFAULT:
1539 ND_PRINTK(2, warn,
1540 "Redirect: from host or unauthorized router\n");
1541 return;
1542 }
1543#endif
1544
1545 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
1546 ND_PRINTK(2, warn,
1547 "Redirect: source address is not link-local\n");
1548 return;
1549 }
1550
1551 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
1552 return;
1553
1554 if (!ndopts.nd_opts_rh) {
1555 ip6_redirect_no_header(skb, dev_net(skb->dev),
1556 skb->dev->ifindex);
1557 return;
1558 }
1559
1560 hdr = (u8 *)ndopts.nd_opts_rh;
1561 hdr += 8;
1562 if (!pskb_pull(skb, hdr - skb_transport_header(skb)))
1563 return;
1564
1565 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
1566}
1567
1568static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb,
1569 struct sk_buff *orig_skb,
1570 int rd_len)
1571{
1572 u8 *opt = skb_put(skb, rd_len);
1573
1574 memset(opt, 0, 8);
1575 *(opt++) = ND_OPT_REDIRECT_HDR;
1576 *(opt++) = (rd_len >> 3);
1577 opt += 6;
1578
1579 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt,
1580 rd_len - 8);
1581}
1582
1583void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
1584{
1585 struct net_device *dev = skb->dev;
1586 struct net *net = dev_net(dev);
1587 struct sock *sk = net->ipv6.ndisc_sk;
1588 int optlen = 0;
1589 struct inet_peer *peer;
1590 struct sk_buff *buff;
1591 struct rd_msg *msg;
1592 struct in6_addr saddr_buf;
1593 struct rt6_info *rt;
1594 struct dst_entry *dst;
1595 struct flowi6 fl6;
1596 int rd_len;
1597 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL,
1598 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
1599 bool ret;
1600
1601 if (netif_is_l3_master(skb->dev)) {
1602 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
1603 if (!dev)
1604 return;
1605 }
1606
1607 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
1608 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
1609 dev->name);
1610 return;
1611 }
1612
1613 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) &&
1614 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1615 ND_PRINTK(2, warn,
1616 "Redirect: target address is not link-local unicast\n");
1617 return;
1618 }
1619
1620 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT,
1621 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex);
1622
1623 dst = ip6_route_output(net, NULL, &fl6);
1624 if (dst->error) {
1625 dst_release(dst);
1626 return;
1627 }
1628 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
1629 if (IS_ERR(dst))
1630 return;
1631
1632 rt = (struct rt6_info *) dst;
1633
1634 if (rt->rt6i_flags & RTF_GATEWAY) {
1635 ND_PRINTK(2, warn,
1636 "Redirect: destination is not a neighbour\n");
1637 goto release;
1638 }
1639 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1);
1640 ret = inet_peer_xrlim_allow(peer, 1*HZ);
1641 if (peer)
1642 inet_putpeer(peer);
1643 if (!ret)
1644 goto release;
1645
1646 if (dev->addr_len) {
1647 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target);
1648 if (!neigh) {
1649 ND_PRINTK(2, warn,
1650 "Redirect: no neigh for target address\n");
1651 goto release;
1652 }
1653
1654 read_lock_bh(&neigh->lock);
1655 if (neigh->nud_state & NUD_VALID) {
1656 memcpy(ha_buf, neigh->ha, dev->addr_len);
1657 read_unlock_bh(&neigh->lock);
1658 ha = ha_buf;
1659 optlen += ndisc_redirect_opt_addr_space(dev, neigh,
1660 ops_data_buf,
1661 &ops_data);
1662 } else
1663 read_unlock_bh(&neigh->lock);
1664
1665 neigh_release(neigh);
1666 }
1667
1668 rd_len = min_t(unsigned int,
1669 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen,
1670 skb->len + 8);
1671 rd_len &= ~0x7;
1672 optlen += rd_len;
1673
1674 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
1675 if (!buff)
1676 goto release;
1677
1678 msg = skb_put(buff, sizeof(*msg));
1679 *msg = (struct rd_msg) {
1680 .icmph = {
1681 .icmp6_type = NDISC_REDIRECT,
1682 },
1683 .target = *target,
1684 .dest = ipv6_hdr(skb)->daddr,
1685 };
1686
1687 /*
1688 * include target_address option
1689 */
1690
1691 if (ha)
1692 ndisc_fill_redirect_addr_option(buff, ha, ops_data);
1693
1694 /*
1695 * build redirect option and copy skb over to the new packet.
1696 */
1697
1698 if (rd_len)
1699 ndisc_fill_redirect_hdr_option(buff, skb, rd_len);
1700
1701 skb_dst_set(buff, dst);
1702 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf);
1703 return;
1704
1705release:
1706 dst_release(dst);
1707}
1708
1709static void pndisc_redo(struct sk_buff *skb)
1710{
1711 ndisc_recv_ns(skb);
1712 kfree_skb(skb);
1713}
1714
1715static int ndisc_is_multicast(const void *pkey)
1716{
1717 return ipv6_addr_is_multicast((struct in6_addr *)pkey);
1718}
1719
1720static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb)
1721{
1722 struct inet6_dev *idev = __in6_dev_get(skb->dev);
1723
1724 if (!idev)
1725 return true;
1726 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED &&
1727 idev->cnf.suppress_frag_ndisc) {
1728 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n");
1729 return true;
1730 }
1731 return false;
1732}
1733
1734int ndisc_rcv(struct sk_buff *skb)
1735{
1736 struct nd_msg *msg;
1737
1738 if (ndisc_suppress_frag_ndisc(skb))
1739 return 0;
1740
1741 if (skb_linearize(skb))
1742 return 0;
1743
1744 msg = (struct nd_msg *)skb_transport_header(skb);
1745
1746 __skb_push(skb, skb->data - skb_transport_header(skb));
1747
1748 if (ipv6_hdr(skb)->hop_limit != 255) {
1749 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n",
1750 ipv6_hdr(skb)->hop_limit);
1751 return 0;
1752 }
1753
1754 if (msg->icmph.icmp6_code != 0) {
1755 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n",
1756 msg->icmph.icmp6_code);
1757 return 0;
1758 }
1759
1760 switch (msg->icmph.icmp6_type) {
1761 case NDISC_NEIGHBOUR_SOLICITATION:
1762 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
1763 ndisc_recv_ns(skb);
1764 break;
1765
1766 case NDISC_NEIGHBOUR_ADVERTISEMENT:
1767 ndisc_recv_na(skb);
1768 break;
1769
1770 case NDISC_ROUTER_SOLICITATION:
1771 ndisc_recv_rs(skb);
1772 break;
1773
1774 case NDISC_ROUTER_ADVERTISEMENT:
1775 ndisc_router_discovery(skb);
1776 break;
1777
1778 case NDISC_REDIRECT:
1779 ndisc_redirect_rcv(skb);
1780 break;
1781 }
1782
1783 return 0;
1784}
1785
1786static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1787{
1788 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1789 struct netdev_notifier_change_info *change_info;
1790 struct net *net = dev_net(dev);
1791 struct inet6_dev *idev;
1792
1793 switch (event) {
1794 case NETDEV_CHANGEADDR:
1795 neigh_changeaddr(&nd_tbl, dev);
1796 fib6_run_gc(0, net, false);
1797 fallthrough;
1798 case NETDEV_UP:
1799 idev = in6_dev_get(dev);
1800 if (!idev)
1801 break;
1802 if (idev->cnf.ndisc_notify ||
1803 net->ipv6.devconf_all->ndisc_notify)
1804 ndisc_send_unsol_na(dev);
1805 in6_dev_put(idev);
1806 break;
1807 case NETDEV_CHANGE:
1808 change_info = ptr;
1809 if (change_info->flags_changed & IFF_NOARP)
1810 neigh_changeaddr(&nd_tbl, dev);
1811 if (!netif_carrier_ok(dev))
1812 neigh_carrier_down(&nd_tbl, dev);
1813 break;
1814 case NETDEV_DOWN:
1815 neigh_ifdown(&nd_tbl, dev);
1816 fib6_run_gc(0, net, false);
1817 break;
1818 case NETDEV_NOTIFY_PEERS:
1819 ndisc_send_unsol_na(dev);
1820 break;
1821 default:
1822 break;
1823 }
1824
1825 return NOTIFY_DONE;
1826}
1827
1828static struct notifier_block ndisc_netdev_notifier = {
1829 .notifier_call = ndisc_netdev_event,
1830 .priority = ADDRCONF_NOTIFY_PRIORITY - 5,
1831};
1832
1833#ifdef CONFIG_SYSCTL
1834static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
1835 const char *func, const char *dev_name)
1836{
1837 static char warncomm[TASK_COMM_LEN];
1838 static int warned;
1839 if (strcmp(warncomm, current->comm) && warned < 5) {
1840 strcpy(warncomm, current->comm);
1841 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n",
1842 warncomm, func,
1843 dev_name, ctl->procname,
1844 dev_name, ctl->procname);
1845 warned++;
1846 }
1847}
1848
1849int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
1850 size_t *lenp, loff_t *ppos)
1851{
1852 struct net_device *dev = ctl->extra1;
1853 struct inet6_dev *idev;
1854 int ret;
1855
1856 if ((strcmp(ctl->procname, "retrans_time") == 0) ||
1857 (strcmp(ctl->procname, "base_reachable_time") == 0))
1858 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default");
1859
1860 if (strcmp(ctl->procname, "retrans_time") == 0)
1861 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos);
1862
1863 else if (strcmp(ctl->procname, "base_reachable_time") == 0)
1864 ret = neigh_proc_dointvec_jiffies(ctl, write,
1865 buffer, lenp, ppos);
1866
1867 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) ||
1868 (strcmp(ctl->procname, "base_reachable_time_ms") == 0))
1869 ret = neigh_proc_dointvec_ms_jiffies(ctl, write,
1870 buffer, lenp, ppos);
1871 else
1872 ret = -1;
1873
1874 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) {
1875 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME))
1876 idev->nd_parms->reachable_time =
1877 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME));
1878 idev->tstamp = jiffies;
1879 inet6_ifinfo_notify(RTM_NEWLINK, idev);
1880 in6_dev_put(idev);
1881 }
1882 return ret;
1883}
1884
1885
1886#endif
1887
1888static int __net_init ndisc_net_init(struct net *net)
1889{
1890 struct ipv6_pinfo *np;
1891 struct sock *sk;
1892 int err;
1893
1894 err = inet_ctl_sock_create(&sk, PF_INET6,
1895 SOCK_RAW, IPPROTO_ICMPV6, net);
1896 if (err < 0) {
1897 ND_PRINTK(0, err,
1898 "NDISC: Failed to initialize the control socket (err %d)\n",
1899 err);
1900 return err;
1901 }
1902
1903 net->ipv6.ndisc_sk = sk;
1904
1905 np = inet6_sk(sk);
1906 np->hop_limit = 255;
1907 /* Do not loopback ndisc messages */
1908 np->mc_loop = 0;
1909
1910 return 0;
1911}
1912
1913static void __net_exit ndisc_net_exit(struct net *net)
1914{
1915 inet_ctl_sock_destroy(net->ipv6.ndisc_sk);
1916}
1917
1918static struct pernet_operations ndisc_net_ops = {
1919 .init = ndisc_net_init,
1920 .exit = ndisc_net_exit,
1921};
1922
1923int __init ndisc_init(void)
1924{
1925 int err;
1926
1927 err = register_pernet_subsys(&ndisc_net_ops);
1928 if (err)
1929 return err;
1930 /*
1931 * Initialize the neighbour table
1932 */
1933 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl);
1934
1935#ifdef CONFIG_SYSCTL
1936 err = neigh_sysctl_register(NULL, &nd_tbl.parms,
1937 ndisc_ifinfo_sysctl_change);
1938 if (err)
1939 goto out_unregister_pernet;
1940out:
1941#endif
1942 return err;
1943
1944#ifdef CONFIG_SYSCTL
1945out_unregister_pernet:
1946 unregister_pernet_subsys(&ndisc_net_ops);
1947 goto out;
1948#endif
1949}
1950
1951int __init ndisc_late_init(void)
1952{
1953 return register_netdevice_notifier(&ndisc_netdev_notifier);
1954}
1955
1956void ndisc_late_cleanup(void)
1957{
1958 unregister_netdevice_notifier(&ndisc_netdev_notifier);
1959}
1960
1961void ndisc_cleanup(void)
1962{
1963#ifdef CONFIG_SYSCTL
1964 neigh_sysctl_unregister(&nd_tbl.parms);
1965#endif
1966 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl);
1967 unregister_pernet_subsys(&ndisc_net_ops);
1968}